[From the Proceedings of the California Academy of Sciences, April 7, 1873.] 



Descriptions of a New Genus and two New Species of Nudi- 

 branchiate MoUusks from the Coast of California. 



BY ROBERT E. C. STEARNS. 



Genus LATERIBRANCHI^A, Stearns. 

 Animal like Triopa, with a single series of gills on each side, central or sub- 

 central and opposite. 



Fig. 1, (f). 



Fig. 2, (f ). 



LATERIBBANCHI^A FESTIVA, StearnS, FiG. 1. 



Body slug-shaped, about one inch long ; of a translucent cream white color on 

 back, ornamented with looped linear markings on each side, of an opaque chalky 

 white, and three irregular, ring-shaped markings of the same color, nearly equi- 

 distant and along a central line on the back, also marked with a few inconspic- 

 uous irregularly placed orange spots ; cephalic tentacles short, clavate, stumpy, 



