40 MacFaiiand — Preliminary Account of Dorididas. 



Glans penis bluntly conical, short, unarmed ; the vas deferens very long 

 and narrow passing into the thick prostate gland ; vagina unarmed ; ves- 

 tibular gland present. 



Found in rocky tide-pools, rather rarely. Species named in recognition 

 of the willing cooperation of my colleague Dr. Harold Heath in collecting 

 Pacific Coast Nudibranchs. 



4. Rostanga pulchra sp. nov. 



Type from Monterey Bay, Calif No. 181,292, U. S. National Museum. 



Body elliptical, depressed, the sides nearly parallel, the ends of the body 

 equally rounded, the mantle ample, concealing the whole body except the 

 tip of the tail. General ground-color bright red, varying from light yellow- 

 ish red to deep scarlet, the back sprinkled evei'y where with minute l)rown 

 and black spots between the papillae ; the number of these spots highly 

 variable, in some cases being few, in others many and thickly set and often 

 grouped into small patches thus deepening the general color of the animal 

 to a reddish brown. 



Dimensions of largest individual taken : length, 18 mm. ; width, 10 mm. ; 

 height, 5.5 mm. ; the average size usually found, however, is from 8 to 12 

 mm. in length. 



Dorsum covered everywhere with small closely set hispid papillae 

 strengthened by divergent spicules extending from base to apex, the cen- 

 tral portion of the apical end being sunken and surrounded by a higher 

 margin, elevated at intervals by the spicules into pointed projections. 

 Sides of foot nearly parallel, abruptly rounded in front, more tapering be- 

 hind ; anterior margin deeply bilabiate, the upper more prominent lip 

 with a median notch ; oral tentacles long, slender, tapering. General color 

 of the ventral surface of the foot, mantle, and sides of body a lighter red 

 than dorsum, rarely with fine black sprinklings. Rhinophores short, 

 stout, the stalk stout, conical, prolonged above the clavus as a blunt cylin- 

 drical process, nearly one-fourth length of whole organ ; clavus perfoliate 

 bearing from 20 to 24 nearly vertical triangular leaves (10 to 12) on either 

 side, the leaves increasing regularly in size from before backward ; sheath 

 of the rhinophore low, papillate similarly to the general dorsum; 

 branchial plumes 10 to 12 erect, separate, com[)letely retractile into a 

 common cavity the margin of which is similar to that of the rhinophore. 

 Labial armature a crescentic band of flattened hooks upon the upper 

 half of each side of the opening, the concave border directed forward, the 

 upper point much in advance of the lower; elements of the armature in 

 5 closely overlapping rows, the tips of the anterior row blunted, those of 

 the posterior rows smaller and pointed ; radula broad, colorless, the median 

 groove deep; teeth in 65 to 80 rows, with 81 teeth in each row ; rhachis 

 naked ; first pleural tooth thick and stout, the base shoi't and broad,'the 

 hook blunt, heavy, slightly curved and bearing 8 to 11 small denticles upon 

 its inner margin ; the succeeding 10 pleural teeth with large, broad base 

 bearing a wing-like expansion upon outer border overlapping adjacent 



