86 



Bryant Waj.kkr 



Fig. 226 



Shell oval, relatively thick, nepeonic-shell 

 passing into the adult without any distinct d;-- 

 marcation ; anterior end shorter ; surface usually 

 concentrically striate or sulcate; cardinal teeth 

 small but distinct. 



Type : Tellina cornea L. 



Example: S . sulcatum {hdjn..) , ^g. 226. Animal, 

 fig. 227. 



Fig. 227 



aa. — Anterior adductor muscle. 



ao.^-Anterior aorta. 



arp. — Ant. retractor pedis muscle. 



as. — Ant. adductor muscle scar. 



au. — Auricle. 



b. — Byssal gland rudiment. 



bls.^ — -Blood space. 



bs. — Branchial siphon. 



c. — Cloacal chamber. 



eg. — Cerebral ganglion. 



cr. — Chitinous rods. 



cs. — Cloacal siphon. 



f.— Foot. 



fil.— Gill filament. 



fj. — Inter-filamentar junctions. 



g. — Inner gill. 



o. — Inhalent ostea. 

 1. — Liver. 



Ip. — Labial palpus. 



m. — Mantle. 



oB. — Organ of Bojanus. 



oe. — (Esophagus. 



og. — Outer gill. 



ot. — Otocyst. 



ov. — Ovarian follicle. 



p. — Pericardial cavity. 



pa. — Posterior adductor muscle. 



pg. — Pedal ganglion. 



prp. — Post, retractor pedis muscle. 



ps. — Post, adductor muscle scar. 



psg. — Parieto-splanchnic ganglion, 



r. — Mantle ridge. 



ro. — Reproductive organs. 



t. — Male follicle. 



vt. — Ventricle. 



wt. — Water-tube. 



