54 Mac Farland— Preliminary Account of Dorididas. 



outer posterior angles, in front united into a veil with undulating margin ■;: 

 labial armature a ring of very short thickened rods; radiila very narrow, 

 the rhachis naked ; the first pleural tooth long, erect, hooked, the outei- 

 one flattened, horizontal, denticulate. Glans penis armed. 



This new genus is dedicated to Mr. Timothy Hopkins, through whose 

 generous interest in Biology the foundation of the Hopkins Seaside Labora- 

 tory was rendered possible. Its type is the following new species. 



20. Hopkinsia rosacea sp. nov. 



Ti/pe from Monterey Bay, Calif. No. 181 ,275, U. S. National Museum. 



General bod\' outline elongate-elliptical, the ends abruptly rounded; 

 mantle firm, densely spiculate, much depressed, sloping gradually outward 

 to the thin margin of the foot, no mantle margin being present ; foot broad, 

 abruptly rounded behind, in front with a broad triangular notch with 

 slightly thickened margin, the remaining margins thin and undulating; 

 head broad, the oral tentacles very broad and united in front forming a 

 thin velar expansion with undulating margin, the rounded posterior angles 

 slightly auriculate; dorsum thicky set everywhere with long gently taper- 

 ing cylindrical soft papula, the tips pointed or occasionally branched,, 

 many one-half to two-thirds the length of the whole animal ; rliinophores 

 perfoliate, cylindro-conical, without sheaths, perfoliate with about 20 leaves,, 

 the clavus making up three-fourths of whole rhinophore ; branchise 7 to 

 14, erect, simply pinnate, separate, arranged in a semi-circ;le or horseshoe- 

 form, the ends directed backward ; reproductive openings incons])icuous, 

 on right side oj)posite rliinophores just below the outermost row of papilla;. 



Color everywhere a beautiful deep rose pink. 



Length of large individual, 20 mm. ; width, 16 mm. ; height of body 

 alone, 5 mm. ; length of longest dorsal papillae, 18 mm. 



Pharyngeal crop strong, ellii)soidal, attached by a very short narrow 

 petiole; labial armature a ling of short thick nxllets in tesselated arrange- 

 ment, width of armature, .4 mm; radula narrow, the teeth in 16 rows; 

 rhachis very narrow, naked ; pleural teetli single eiect, long, flattened, the 

 base triangular, broad forming about one-third of whole length, the shaft 

 flattened blade-like, at the distal end a small blunt hook, total length, .6S 

 mm.; the single uncinal tooth is much smaller, thin, depressed, triangular, 

 nearly horizontal, the posterior margin more or less pointed and irregularly 

 denticulate, length, .08 or .09 mm.; greatest width, .076 mm. Prostate 

 gland very large, forming one-half of whole bulk of anterior genital 

 mass ; glans penis armed with minute hooks. 



Occurring under shelving rocks between tide-marks all along the coast 

 from Monterey to Point Lobos ; not rare. 



Stanford University, California. 



^ 



