Four specimens found with the last, differ from the type only in having the black spots very small. The tentacles are acute, cylindro-conic, retractile into a cavity bordered by a toothed membrane. The branchiæ form an erect chimney-shaped expansion. I cannot discover the stellate valvular structure of the branchial opening, which characterises the genus _Asteronotus_, in these specimens. _Doris Sandiegensis_ Cooper, loc. cit. Two found with the last agree exactly with specimens from San Diego. The tentacles are conical and acute. The branchial orifice does not present the peculiar characters of _Actinocyclus_. Although all these species differ to some extent, they have no characters to distinguish them generically from the typical _Doris_, unless anatomical or microscopical examination should reveal them, or the characters of that genus should be more closely limited. TRIOPA Johnston, 1838. _T. catalinæ_ Cooper. State coll. species, 1002. Form much elongated, narrow, dorsal surface flat, becoming spatulate posteriously. Head expanded laterally and flattened, wider than the body, ornamented with 14 ciliæ, equally distributed around its margin, so as to form nearly a circle. Tentacles long, conical, retractile. Three pairs of short ciliæ at equal distances apart between the tentacles and middle of the body, connected by the sharp edges of the dorsal surface. Branchial plume five parted, bipinnately divided, expanding to nearly twice the width of the body, situated a little behind the middle of the body. Two short ciliæ close together on the medium line, a little behind the branchiæ. Length 1.50, breadth 0.25 inch. Color yellowish, speckled with white, filaments vermilion red. Four specimens found on sea weed among rocks at low water near north end of Catalina Island, June 16th. DENDRONOTUS Alder and Hancock, 1845. _D. iris_ Cooper. State coll. species 959. Pale purple, varying to orange red, foot narrowly edged with white, tentacles with white tips and a subterminal orange ring, branchial processes purple, the smaller ones sometimes olive near the base. Length of largest specimens 3, breadth 0.50 inch. Several found on the beach at Santa Barbara, May 5th, having been washed ashore by an unusually heavy sea, occurring at a very low stage of the tide. One, also, dredged on seaweed, from a depth of 28 fathoms, two miles off shore. This species seems more variable in color than the other _nudibranchiata_ of this coast, but I saw no reason for considering them of more than one species. Those washed ashore being somewhat injured, although still alive, I made no drawing of them, and the more perfect one dredged was too small for this purpose.