Species descriptions

Pteria kitakamiensis Hayami, 1958

Description:

"Shell highly inequivalve, trigonal, pteriform, compressed; test thin; left valve moderately inflated but right valve is nearly flat; hinge-margin straight, almost as long as whole shell-length; anterior margin long, almost straight, forming an angle of 40 degrees or so with hinge-margin; ventral margin short, abruptly curved; posterior one slightly sinuated in dorsal half, forming a small pointed posterior auricle; anterior wing large, elongated along anterior margin, defined from shell-body by an obscure groove in right valve; umbo fairly protruded above hinge line in left valve, but not in right; surface marked with with more or less fluctuated concentric lamellae; inner surface of left valve undulated by some broad radial plications; hinge and ligament structures unknown." [Hayami, 1958 : 163.]

Type material illustration:

Hayami, 1958: pl. 24, fig. 10 [paratype, MM 2738], 11 [holotype, MM 2737].

Typification:

"Holotype (MM 2737) Right external mold Length 38.5 mm, height 24.0 mm, thickness 1.5 mm

Paratype (MM 2738) Left internal mold Length 36.0+ mm, height 21.5+ mm, thickness 7.5 mm"

[Hayami, 1958 : 163.]

Thu, 2008-01-31 22:24 -- ilya
Bakevellia trigona (Yokoyama, 1904)

Taxonomic status and synonymy:

Gervillia trigona Yokoyama, 1904 [original description].

Bakevellia trigona (Yokoyama, 1904). - Hayami, 1957 : 52, 52, pl. 2, fig. 1-5 [revision of Liassic Bakevellia of Japan].

Wed, 2008-01-30 21:21 -- ilya
Pteria (Austropteria) dendronephthya Habe, 1960

Additional information:

"This new species commonly attaches to the species of Dendronephthya, D. castanea Utinomi and its allied forms, by the byssus as in the other pterid species at Tomioka, Amakusa. [...] The habitat of this species is also unique in attaching to soft alcyonarians." [Habe, 1960 : 290.]

Distribution:

"Tanabe Bay, Wakayama Pref." [Habe, 1960 : 290.]

Geological age:

Recent.

Description:

"Shell rather small for the genus, light yellow to brownish black,
sometimes clouded by the black blotches along the growth lines or
reddish radial rays, oblique. Left valve larger and more inflatedthan
the right. Posterior wing extends backwards, forming the rather shallow
posterior sinuation. Anterior winged area rather small, triangular,
pointed to the anterior end and covered with the rough periostracum, on
which prickly cords radiate from the umbo. In the right valve
antero-ventral margin has a byssal incurvation from which the byssus
comes out. The median area rather smooth, large and elongated
postero-ventrall." [Habe, 1960 : 289.]

Taxonomic notes:

"This differs from the allied forms P. brevialata (Dunker), P. cypsellus (Dunker) and P. loveni (Dunker), which are also collected from the same locality, in having the shell not exceeded 30 mm in length even in the adult form, with a short posterior wing, the end of which is shorter than the posterior end of the median area of the shell." [Habe, 1960 : 290.]

Type locality:

"Tomioka, Amakusa, Kumamoto Pref." [Habe, 1960 : 290.]

Typification:

"Length 28.5 mm, height 16.3 mm, and breadth 9.3 mm (conjoined valves) (type specimen)

Length 29.5 mm, height 19.2 mm, and breadth 8.5 mm (conjoined valves) (paratype specimen)

Length 26.0 mm, height 14.0 mm, and breadth 7.3 mm (conjoined valves) (paratype specimen)

Length 27.8 mm, height 16.9 mm, and breadth 9.2 mm (conjoined valves) (paratype specimen)

Length 21.2 mm, height 12.4 mm, and breadth 5.7 mm (conjoined valves) (paratype specimen)"

[Habe, 1960 : 289-290.]

Fri, 2008-01-18 23:47 -- ilya

Malvufundus irregularis Jousseaume, 1894

Geological age:

Recent.

Description:

"Testa irregularis, depressa, fere ovalis, antice et postice inaequaliter biolata, corneo-cutea, maculis nigrescentis irregulariter aspersa, concentrice striata, versus apicem lamellis concentrice instructa, cauda curcata, ala longissimaa fisso a cauda disjuncto.

Dimensions; haut., 30 millimétres; larg., 52 millimétres; épaiss., 7 millimétres.

Hab.: Japon." [Jousseaume, 1894: 228.]

Type locality:

"Japon" [Jousseaume, 1894: 228].

Type material illustration:

Habe, 1953 : pl. 9, fig. 3, 4 [black-and-white photos of RV exterior and interior surfaces].

Fri, 2008-01-18 23:05 -- ilya

Perna nana Gould, 1850

Geological age:

Recent.

Description:

"T. parva, crassa, subquadrata, adunca, lamellosa, extus nigra; margine ventrali sinuato; angulo infero-posteriori rotundato; latere postico sinuato: area cardinali lata, 6-sulcata; fissura byssali ampla, trigonalis: margarita plumbaginea; limbo corticali angusto, pallido. Long. ⅗; alt. ¾; lat. ¼ poll. Hab. Feejee Islands; inder stones. Drayton.

The solidity and color of this little species will not admit of its being confounded with any other species. It bears the marks of mature age." [Gould, 1850: 312.]

Type locality:

"Hab. Feejee Islands." [Gould, 1850: 312].

Thu, 2008-01-03 23:53 -- ilya

Perna eremita Gould, 1850

Geological age:

Recent.

Description:

"T. fragilis, exaluminata, variabilis, dolabrata, vulsellata, unguiformis, pectiniformis et omnimodè distorta, plerumque radiatim rugoso-striata et in junioribus rufolineata; antrorsum plus minusve curvata: marginata argentea; limbo corticali ampliat, foliaceo, stramineo, vitro: margine cardinali ferè horizontali, 6-8 sulcato; fissurâ byssali profundâ. Long. 2; alt. 1 9/10; lat. ⅜ poll. Inhabits Carlshoff Island, Paumotu Group.

This shell, though so variable as to elude all terms of description, is still very distinct from all others, in all its forms. It seems to acquire its multiform shapes from the cavities in coral where it resides. Young or well protected specimens are sculptured by delicate radiating ramose ribs bearing minute scales." [Gould, 1850: 311.]

Type locality:

"Inhabits Carlshoff Island, Paumotu Group" [Gould, 1850: 311].

Thu, 2008-01-03 23:29 -- ilya

Perna torva Gould, 1850

Geological age:

Recent.

Description:

"T. rudis, crassa, inequivalvis, concentricè lamellata, cinerea, obliqua, trapezoidea; latere byssali dilatato, semicirculari; sinu byssali profundo; apice adunco; latere postico rectilineari, obliquo, producto; margine cardinali obliquo: area cardinalis triangularis, sulcis obliquis ad sex arata: margarita ex argenteo-purpurasens; limbo lato, retrò. Long. 2½; alt. 1¾; lat. ⅜ poll. Hab. Sandwich Islands.

The obliquity of this species and the small number of its cardinal sulci are among its most prominent characters." [Gould, 1850: 311.]

Type locality:

"Hab. Sandwich Islands" [Gould, 1850: 311].

Thu, 2008-01-03 23:03 -- ilya

Perna argillacea Gould, 1850

Geological age:

Recent.

Description:

"T. solidula, mutica, compressa, elongata, anticè dilatata, posticè subrecta, ex luteo alutacea, hic illic nigricans; apice adunco: fissura byssali angusta, lanceolata: intus livescens: area cardinalis curta, obliqua, triangularis, sulcis obliquis at 8 arata: fovea apicaliss profunda. Long. 2½; alt. 3; lat. ⅜ poll. Hab. ?

The resemblance to the common P. ephippium of the West Indies is very great. It differs chiefly in the clay-colored exterior, and in having the byssal instead of the opposite side dilated; the muscular scar is also smaller." [Gould, 1850: 311.]

Type locality:

"?" [Gould, 1850: 311].

Thu, 2008-01-03 22:36 -- ilya

Crenatula pergaminea Gould, 1850

Geological age:

Recent.

Description:

"T. membranacea, obliquissima, subfalcata, concentricè laminoso-fibrosa, albida, lineis lacteis radiata; margine dorsali recto, umbonibus tumidis, acutis, ad trientem anteriorem sitis; latere postico obliquè trancato; areâ cardinali angusta ad 5-crenata: intus sub-margaritacea. Long 1¼; alt. ⅝; lat. ⅜ poll. Hab. Feejee Islands.

None of the species already described agree with this in color, texture, pr form. Its structure is very delicate and unresisting, almost fibrous at its edge." [Gould, 1850: 310-311.]

Type locality:

"Feejee Islands" [Gould, 1850: 311].

Thu, 2008-01-03 22:07 -- ilya

Pteroperna kitadaniensis Goto, 1983

Distribution:

"Black mudstone at the lower (?) Pliensbachian Negoya Formation of the Kitadani, Asahi-machi, Shimoniikawa-gun, Toyama Prefecture." [Goto, 1983: 83.]

Geological age:

Lower (?) Pliensbachian, Lower Jurassic [Goto, 1983].

Description:

"Shell is small, inequivalve, pteriform, left valve more strongly convex than right. Hinge-margin is straight, fairly long. Anterior wing is large, triangular in right valve, subtriangular with a rounded anterior extremity in left valve. Posterior wing with three longitudinal ridges is long, sharply pointed backwards, with remarkably sinuated posterior margin; umbo located at about a fifth of hinge-line from anterior end, fairly protruded above hinge-margin in left valve, but not in right; surface marked with fluctuated concentric lamellae." [Goto, 1983: 83.]

Type material illustration:

Goto, 1983: pl. 15, fig. 3, 4.

Typification:

Holotype: P.31102, internal and external molds of LV; paratype: P.1102, nternal and external molds of RV. [Goto, 1983: 83.]

Thu, 2007-12-13 20:55 -- ilya

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