92 PROCEEDINGS OF THE ACADEMY OF [Feb., 



AA. — Sexes dimorphic, the males much reduced and degenerate in 

 structure; corresponding with this condition is a 

 dimorphism of the ova. Ovary unpaired. Only- 

 one band of cilia borne on each trunk segment, with 

 the exception of the last, which may bear two. 

 B. — Trunk segments 6. 

 C. — Body not covered with a coat of cilia between the bands. 

 D. — Circumanal band present. 

 E. — Cephalic bands without dorsal interruptions; anterior 

 pair of nephridia simple, . . . gyrociliaius. 



EE. — Cephalic bands with dorsal interruptions; anterior pair 



of nephridia complex, conklini. 



DD. — Circumanal band wanting, apatris. 



CC. — Body covered with a coat of cilia between the bands, 



metameroides. ^ 

 BB. — Trunk segments 5, pygmceus. 



List of Species of Dinophilus. — 



1. Dinophilus vorticoides.' 



Schmidt, 1848.— Sclmltze, 1849.— Diesing, 1850.— Beneden, 1851.— Quatre- 

 fages, 1851.— Beneden, 1861.— Diesing, 1862.— Graff, 1882.— Weldon, 

 1886.— Harmer, 1889a.— Schimkewitsch, 1895.— Schultz, 1902. 



Head equal in width to first trunk segment, bearing two ciliated 

 bands; the first with a dorsal gap (Schimkewitsch), the second uninter- 

 rupted. Ovaries four-lobed. Color, orange. Length, (?). Habitat^ 

 Faroe Islands (Schmidt), Belgian coast (Beneden), White Sea (Mer- 

 eschkowsky, Schimkewitsch). 



2. Dinophilus gardineri. 



Moore, 1899.— Schultz, 1902. 

 Head not wider than first trunk segment, bearing two ciliated 

 bands(?). Body covered with a coat of cilia in addition to the ciliated 

 bands. Caudal appendage short. Color, orange red. Habitat, brackish 

 pools. Woods Hole, Massachusetts, U. S. A. 



3. Dinophilus taeniatus. 



Harmer, 1889, 1889a.— Schimkewitsch, 1895.— Schultz, 1902.— Shearer. 

 1906. 



Head slightly narrower than first trunk segment, bearing two 

 uninterrupted ciliated bands. Circumanal band present. Female 

 with ovaries four-lobed, male with a median penis and lateral seminal 



' That this species is dimorphic is assumed on the ground that Hallez found no 

 male.s. If this assumption is correct it is probable that the ovary is unpaired. 



' Graff (1882), following Diesing (1850), considers this species identical with 

 Vortex capitata Oersted (1843) and Goniocarena capitata Schmarda (1859). 

 Oersted's original description being inaccessible, it seemed advisable to allowr 

 Schmidt's name to stand pro^•isionally. 



