504 MOLLUSCA 



cerata fusiform with an orange-colored interior, arranged in transverse 

 groups of 3 or 4; length 30 mm.; width 8 mm.: Cape Cod, northwards. 



3. FLABELLINA Cuvier. Body slender; rhinophores laminated; oral 

 tentacles elongate; cerata on compressed stalks: several species. 



F. bostoniensis (Couthouy). Body drab in color with a silvery line 

 on the tail and the back of the oral tentacles; cerata curve backwards, 

 arranged in 5 or more groups on each side, white-tipped ; length 25 mm. ; 

 width 7 mm.: Cape Cod and northwards. 



4. CORYPHELLA Gray. Front angles of foot elongated to form long 

 lobes: 18 species. 



C. gymnota (Couthouy). Body slender and tapering to a point, 

 white in color ; oral tentacles longer than the dorsal, which have wrinkled 

 sides; cerata arranged in 6 to 10 transverse clusters, with a vermillion 

 interior and white tips; length 25 mm.; width 3 mm.: Woods Hole to 

 Boston. 



C. mananensis (Stimpson). Body white in color; cerata vermillion 

 with white tips; rhinophores brown and wrinkled; length 35 mm.: Cape 

 Cod and northwards. 



FAMILY 2. DOTONIDAE. 



Cerata tuberculated and in a single row on each side, numerous, 

 without nematocysts; tentacles retractile; foot very narrow; a simple 

 veil in front : 4 genera. 



DOTO Oken. With the characters of the family: 4 species. 



D. coronata (Gmelin) (Fig. 767). Body slender; 

 brown or pink in color, but variable; 12 mm. long; 

 cerata large, club-shaped, 5 to 8 on a side, with red 

 spots: New Jersey to Labrador in shallow water, on 

 Bryozoa and hydroids; often common. 



DIVISION 4. ELYSIOIDEA. 



Fig. 767 

 Doto coronata Cerata either present, when they receive extensions 



A, dorsal as- of the liver, or absent ; laws absent ; radula with but 

 pect ; B, one 

 of the cerata. one row of teeth : 3 families. 



Key to the families of Elysioidea: 



Cj Cerata present i r HEBM^IDAE 



a a Cerata absent. 



&! Two lateral ridges present 2. ELYSIIDAE 



6, Ridges absent 3. LIMAPONTIIDAE 



FAMILY 1. HERM^IDAE. 



Cerata present; 1 pair of tentacles, non-retractile or absent; anus 

 dorsal and median: 4 genera. 



