308 American Seashells 



leaves, all told, in the club of the rhinophore. Distinguished from frondosus 

 by the 3 to 5 small but well-marked dendriform papillae on the posterior 

 edge of the rhinophore sheath. Usually dredged down to 25 fathoms. Prob- 

 ably the largest of the American nudibranchs. 



Fa7mly SCYLLAEIDAE 

 Genus Scyllaea Linne 1758 



Scyllaea pelagic a Linne Sargassum Nudibranch 



Southeast United States. Other warm seas. 



I to 2 inches in length. Translucent cream-brown to orange-brown. 

 With numerous flecks of red-brown. Body elongate. Oral tentacles absent. 

 Two slender long rhinophores. Sides of body with 2 pairs of large, club- 

 like, foliaceous gill plumes or cerata. Common in floating sargassum weed 

 in the Gulf Stream. 



Family AEOLIDIIDAE 

 Genus Aeolidia Cuvier 1798 



Body depressed, rather broad; branchiae a httle flattened, set in numer- 

 ous, close, transverse rows; 4 tentacles simple; foot broad, anterior angles 

 acute. Radula of a single, broad, pectinate plate, 



Aeolidia papulosa Linne Papillose Eolis 



Plate i5g 



Arctic Seas to Rhode Island. Europe. Arctic Seas to Santa Barbara, 

 California. 



I to 3 inches in length. Color variable: brown, gray or yellowish, 

 always more or less spotted and freckled with lilac, gray or brown and 

 opaque-white. Number of papillae fcM^er in young specimens. 30 rows in 

 radula of a single, broad, arched tooth bearing about 46 denticles. 



Family TERGIPEDIDAE 



Genus Catriona Winckworth 1941 



(Cratena of authors) 



Catriona aurantia Alder and Hancock Orange-tipped Eolis 



Plate 15J 



Arctic Seas to Connecticut. Europe. 



% inch in length. Branchiae numerous, occurring in 10 or 11 close, 

 transverse rows, anteriorly with 5 to 6 papillae per row, posteriorly with 2 



