CONCHIFERA; 487 



Synonyms, Hypogcoa, Poll. Vagina, Megerle. Ensis, Schum. 

 Ensatella, Sw. 



S/ied very long, sub -cylindrical, straight, or slightly recurved, 

 margins parallel, ends gaping ; beaks terminal, or sub-central ; 



Fig. 264. Solen siliqua, L. -|- ; the valves forcibly opened, and mantle divided as far as 

 the ventral foramen, to show the foot. 



hinge-teeth f '■, ligament long, external ; anterior muscular 

 impression elongated ; posterior oblong ; pallial line extending 

 beyond the adductors ; sinus short and square. 



Animal with the mantle closed except at the front end, and a 

 minute ventral opening ; siphons short, united, fringed ; palpi 

 broadly triangular ; foot cylindrical, obtuse. 



Bistrihidion, 23 species. World-wide except Arctic seas ; — 

 100 fathoms. 



Fossil, 40 species. Carb. — . United States, Europe. 



The Eazor-fishes live buried vertically in the sand, at extreme 

 low water, their position being only indicated by an orifice like 

 a key-hole ; when the tide goes out they sink deeper, often 

 penetrating to a depth of one or two feet. They never volun- 

 tarily leave their burrows, but if taken out soon bury themselves 

 again. They may be caught with a bent wire, and are excellent 

 articles of food when cooked. (Forbes.) 



CuLTELLTJS, Schumacher. 



Tijpe, C. lacteus, PI. XXII., Fig. 5. 



Etymology, cultellus, a knife. 



Shell elongated, compressed, rounded and gaping at the ends ; 

 hinge-teeth 2.3 ; beaks in front of the centre, supported inter- 

 nally by an oblique rib ; pedal impression behind the umbonal 

 rib ; posterior adductor trigonal ; pallial line not prolonged behind 

 the posterior adductor ; sinus short and square. 



Animal (of C. Javanicus) with short, fringed siphons ; gills 

 narrow, half as long as the shell, transversely plaited ; palpi 

 large, angular, broadly attached ; foot Ijirgo, abruptly trun- 

 cated. 



Distrihution, 5 species. Africa, India, Nicobar. 



Bub-genera. Geratisolen^ Forbes. (Polia, D'Orbigny. Pharus, 



