1879.] NATURAL SCIENCES OP PHILADELPHIA. 109 



In the latest of my cited papers was moreover given a supple- 

 ment to the former list of described or denominated Dorides, that 

 could be referred vvitli more or less probability to this group. The 

 number of species amounted to about ninety. 



In external form the Chromodorides somewhat agree with the 

 Goniodorides, but have much more gay and handsome colors, 

 mostly forming longitudinal stripes. The tentacles are small, 

 conical; the (retractile) rhinophoria with densely perfoliatcd club. 

 The margin of the mantle on the anterior and posterior ends de- 

 veloped in a frontal and a caudal veil, which sometimes shows 

 peculiar knots. 1 The (retractile) gill is formed of simpl}- pinnate 

 plumes, sometimes divided at the top. The foot rather narrow. 

 The lip-disk, with an annular hard lamina, composed of densely 

 set small hooks, mostly bifurcated at the top. In the radula no 

 median plates, but often on the rhachis peculiar thickenings 

 (pseudo-plates). The lateral plates, of ordinary form, nearly 

 always serrulated or denticulated on the margin of the hook. 

 The penis unarmed. 



In the southern part of the Pacific the Chromodorides are repre- 

 sented by a whole series of species ; from the northern part 

 (China) only a few representatives are known ; among the speci- 

 mens sent by Ball only two species were detected, the hitherto 

 known most northern representatives of this group, of which no 

 form has }'et been found in the northern part of the Atlantic. 



Chromodoris Dalli, Bergh, n. sp., Plate XIII. f. 1-7 ; Plate XIV. f. 1-4. 



Hob. Oc. Pacific, sept. (Puget Sound, Washington Territory.) 



An individual of this species was obtained, during the progress 



of the U. S. Boundary Commission, by Dr. Kennerly, the lamented 



naturalist of the U. S. party, in Puget Sound. No notes have 



come to hand in regard to the living animal. 



The animal preserved in spirits was 11.5 mm. long, 5.5 broad, 

 and 4.2 mm. high. The height of the rhinophoria was 1.25 mm., 

 of the tentacula 0.75 mm., of- the branchial leaves 2.0 mm.; the 

 breadth of the mantle margin 1.2 mm., of the foot 2.5 mm., and 

 the length of the tail was 2.5 mm. The ground-color of the back 

 and sides isabelline-gray, everywhere covered with small, and 

 still smaller, coal-black, rounded points about 0.25 mm. in dia- 



' Such knots have been found (by me) in the Ghr. runcinata, picturata, 

 camcena, elegans, glauca, gonaiophora, and Californiemis. 



