90 THE NAUTILUS. 



Tliis interesting addition to the genus has a sharper spire than any 

 other species and a different sculpture. It is perhaps nearest L. 

 canaliculatus Dall, which has coarser sculpture and a channeled suture. 



A NEW TETHYS FROM CALIFORNIA. 



BY T. D. A. COCKERELL. 



Tethys (Neaplysia) ritteri, n. sp. 



Length 21 cm., breadth about 8 cm. Dark grayish-olivaceous; 

 sides with oblique, flame-like, blood-red markings, especially about 

 the middle of the body ; upper surface of the head and outer surface 

 of epipodial lobes mottled with brown, but without any conspicuous 

 blotches ; inner surface of epipodial lobes and mantle covering shell 

 pale sea-green, wholly without markings ; lobe overlapping branchia? 

 deep rich purple ; when the shell is removed, the area beneath it is 

 seen to be strongly suffused with dark purple ; branchice purplish- 

 grey ; sole 45 mm., broad, transversely grooved and corrugated, 

 greyish-brown, inclining to coffee-color ; epipodial lobes about 80 mm. 

 long and 28 broad, from base within ends of lobes to nearest part of 

 sole about 67 mm.; anterior tentacles 11 mm. from inner base to tip; 

 posterior tentacles 14 mm. long. 



Shell very thin, flexible, corneous, 58 mm. long, 42 broad ; acces- 

 sory plate well-developed. 



The animal produces an abundance of a reddish-brown fluid. The 

 muscular stomach or gizzard contains eleven pentagonal corneous 

 bodies, which fit raised areas on its wall. The largest of these bodies 

 was 14 x 10^ x 10^ mm. The alimentary canal contained seaweed. 



Hab.: San Pedro, California. The specimen described was found 

 cast up on the shore of the bay, just in front of the University of 

 California Marine Laboratory, July 23, 1901. Others were obtained 

 by workers at the laboratory ; one of these, which I saw, had been in 

 formalin, and the red, flame-like markings had wholly disappeared. 



This animal has the structure of T. califomicus (Cooper), which 

 was also described from San Pedro, but the color-scheme is so entirely 

 different that it must be assumed that the species are distinct. Should 

 any reason hereafter appear to the contrary, T. ritteri will at least be 

 a very distinct variety. It is named after Prof. Wm. E. Ritter, 



