458 



MOLLUSCA 



PHYLÜM VI 



sculptured, nearly equivalve, with small, iinequal ears, and deep byssal notch with well- 

 developed ctenolium. Trias to Recent. 



CamjJtonectes Ag. (Fig. 712). Shell small, tliin, nearly smootli, with fine divergent 

 striation radiating from a median line. Jura to Recent. 



Fio. 710. 



Peden (Clüamys) suUextorius 

 Goldf. Coral-Rag ; Nattheim. 



Fio. 711. 



Peden (Chlamys) varius Linn. 

 Pliocene ; Rhodes. 



Fk;. 712. 



Fig. 713. 



Peden (Ento- 



liwrn) cornutus 



Peden {Camptonedes) Uns Qnenst. Upper 



Sovv. Middle Jura ; Baiin, Jura ; Hohen- 



near Cracow. i/^. zolleni. i/i. 



Entoliutn Meek (Fig. 713). Smooth, thin, with sub-equal ears diverging at a sharp angle 

 above the beaks ; byssal notch obsolete. Carboniferous to Cretaceous. 



Pseudamusium Adams. Shell small, thin, glassy ; the posterior ear obsolete, byssal notch 

 distinct. Cretaceous to. Recent. Syncyclonema Meek is scarcely different. 



Amusium Bollen (Fig. 714). Shell with raised radial riblets interiially ; ex- 



FiG. 714. 

 Ämuslwin cristatus (Bronn). Miocene Baden, near Vienna. l/i. 



Fig. 715. 



Hinnites ahjcdus (Phill.). 

 Middle Jura ; Baiin, near 

 Cracow. i/i. 



ternally smootb. or delicately sculptured ; valves large, flattish, with sub-equal ears ; 

 byssal notch inconspicuous or absent. Lias to Eecent. 



Subgenus : Propeamusium Greg. Small, thin, abyssal^, often with relatively conspicuous 

 sculpture, usually discrepant on the valves. Tertiary and Recent. 



Hinnites Defr. (Fig. 715). Shell free and Pectiniform when young, later adherent 

 to other objects and more or less distorted. Trias to Eecent. 



Pedum Brug. Shell with an alivincular ligament in an oj)en groove and area like 

 that of Spondylus in the adult ; the young like Ghlamys. Eecent ; sessile on corals. 



Family 34. Spondylidae Fleming. 



Shell inequivalve, nearly equilateral, closed, 'pectiniform, obscurely auriculate, mono- 

 myarian; sessile; area amphidetic,7nuch larger on the attached valve; ligament alivincular^ 

 rmlium more or less suhmerged ; byssus obsolete; hinge with a taxodont provinculum, 



