COCCULINA. 131 



and S. arabica Riipp. are species enumerated in the Genera of 

 Recent Mollusaa. but of which I haye not seen descriptions. 



Family COCCULINID^E Dall, 1882. 



Shell patelliform, not nacreous, symmetrical, with an entire non- 

 sinuated margin and a posteriorly inclined apex with a (usually 

 deciduous) spiral nucleus ; muscular impression horse-shoe-shaped, 

 interrupted over the head. 



Animal with a prominent head and muzzle, the males with an 

 intromittent organ at the base of the right tentacle ; a single lam- 

 ellose asymmetrical gill (resembling in form and place of attach- 

 ment the gill in Acmsea) between the under surface of the mantle 

 and the upper surface of the body from a point above and behind 

 the head, extending around toward the right, and even backward 

 on the right side ; attached only at its base. Eyes wanting in the 

 known species. Anus anterior, opening in a papilla above and be- 

 hind the head. Mantle margin and sides of foot plain, without 

 epipodial papillae or processes, but they are sometimes present 

 behind. Radula with a small or moderate hardly raised rhachidian 

 tooth (the cusp in one species obsolete), three moderate inner laterals 

 with denticulate cusps, a larger denticulate major lateral with a 

 stout and twisted stalk, and on each side a stout base from which 

 spring numerous slender uncini hooked at their tips. There is no 

 jaw. The dentition resembles in a general way that of Parmophorus 

 and of some species of Helicina. 



Genus COCCULINA Dall, 1882. 



Cocculina Dall Proc. U. S. Nat. Mus. 1881, p. 402 ; Blake Re- 

 port in Bull. M. C. Z., vol. xviii, 1889, p. 345.— Verrill, Trans. 

 Conn. Acad, v, p. 533 ; vi, p. 202.— Jeffreys, P. Z. S. 1883, p. 

 393. — Fischer, Manuel de Conch., p. 841. — Watson, Challenger 

 Gasterop., p. 30. — Tectum sp. Jeffreys, P. Z. S. 1882, p. 672. 



The animal is blind ; the shell colorless, with radiating and con- 

 centric sculpture; other characters are given in the diagnosis of the 

 family. About a dozen species are known, one from the Philippines, 

 the others from the Atlantic. All are deep-sea forms. Dr. Dall 

 divides the genus into two sections : Cocculina s. s., foot having 

 two posterior epipodial filaments, and Coccopygia, foot without 

 epipodial filaments. The last-named section contains C. spinigem 

 Jeffr. 



