136 SAXICAVID^. 



concentric lines ; ligament and basal margins straight, parallel ; 

 a spoon-shaped fosset in each valve, the lateral margins of which 

 are carinated, and the base emarginated. S. siibovata, Conr. 

 Miocene; Virginia. 



Panop^a, Menard de la Groye, 180*1. 



Etym. — Panope, a Nereid. Syn. — Glycimeris, H. and A. Ad. 



Bistr. — 11 sp. Northern seas, Mediterranean, Cape, Australia, 

 New Zealand, Patagonia. Low-water — ninety fathoms. Fossil, 

 140 sp. Inferior Oolite — ; United States, Europe, India. 



Shell equivalve, thick, oblong, gaping at each end ; ligament 

 external, on prominent ridges ; one prominent tooth in each valve ; 

 pallial sinus deep. 



Animal with very long, united siphons, invested with thick, 

 wrinkled epidermis ; pedal orifice small, foot short, thick, and 

 grooved below ; gills long and narrow, extending far, into the 

 branchial siphon, the outer pair much narrower than the inner, 

 faintly pectinated ; palpi long, pointed, and striated. 



In P. Norvegica the pallial line is broken up into a few scat^ 

 tered spots, as in Saxicava ; the animal itself is like a gigantic 

 Saxicava! This species ranges from Ochotsk to the White Sea, 

 Norway, and North Britain ; it was formerly an inhabitant of 

 the Mediterranean, where it now occurs fossil. (= P. Bivonse, 

 Philippi.) The British specimens have been caught, accidentally, 

 by the deep-water fishing-hooks. P. Natalensis is found at Port 

 Natal, buried in the sand at low-water; the projecting siphons 

 first attracted attention (doubtless by the strong jets of water 

 thej- sent up when molested), but the shells were only obtained 

 by digging to the depth of several feet. The Mediterranean 

 species P. glycimeris, attains a length of six or eight inches. 



GLYCIMERIS, Klein, 1753. (Panopsea, H. and A. Adams. 

 Panomj^a, Gray.) Pallial line broken up into punctations, pos- 

 terior impression much lengthened. Recent, miocene and plio- 

 cene. P. glycimeris, Born (cvii, 29-31). 



Cyrtodaria, Paudin, 1799. 



Syn. — Glycimeris, Lam., 1801. 



Distr. — 2 sp. Arctic seas, Cape Parry, Northwestern America, 

 Newfoundland. Fossil. Pliocene — ; Britain, Belgium. C.siliqua, 

 Chemn. (cvi, 17; cvii, 32). 



Shell oblong, gaping at each end ; posterior side shortest ; 

 ligament large and prominent ; hinge thick, without teeth ; 

 epidermis black, extending beyond the margins ; anterior mus- 

 cular scar long, pallial impression irregular, slightly sinuated. 



Animal larger than its shell, subcylindrical ; mantle closed, 

 siphons united, protected by a thick envelope; orifices small; 

 pedal opening small, anterior ; foot conical ; palpi large, striated 

 inside, the posterior border plain ; gills large, extending into the 

 branchial siphon. 



