MacFarland Preliminary Account of Dorididse. 39 



pleurae large strongly hooked, the wing much less strongly developed 

 than in Archidoris montereyensi*. Vas deferens long, slender, arising at its 

 proximal end from the large ovoid whitish-yellow prostate gland which 

 lies upon the upper anterior face of the anterior genital mass ; glans penis 

 unarmed ; vagina unarmed. 



Found in rocky tide-pools all along the coast of Monterey Bay at all 

 seasons of the year but most abundant in the summer. Usually abundant 

 on the piles of the Monterey wharf in company with the preceding smaller 

 species, Archidoris montereyensis, from which it may be readily distinguished 

 by the dark blotches of color of the dorsum being distributed between the 

 tubercles and not upon them, and by the conical oral tentacles, as well as 

 by its much larger size. The largest and most conspicuous Dorid of Mon 

 terey Bay. 



3. Discodoris heathi sp. nov. 



Type from Monterey Bay, Calif. No. 181,282, U. S. National Museum. 



Body elliptical, broad, depressed, dorsum minutely tuberculate, nearly 

 smooth. General color light yellow, becoming darker toward the median 

 line, the dorsum sprinkled everywhere with extremely minute black or 

 brown spots, giving the animal a general dusty appearance ; a variable 

 number of black, brown or brownish-red flecks irregularly scattered over 

 the dorsum, the majority of them in the mid-dorsal region ; mantle margin 

 thin, wide, crenulate, extending far beyond the foot except behind; foot 

 rather narrow, its anterior end abruptly rounded, bilabiate ; upper lip 

 deeply notched. 



The head is small and inconspicuous, being almost concealed between 

 the mantle and foot, oral tentacles long, cylindro-conical ; rhinophores 

 moderately large, clavus perfoliate with 10 to 15 leaves, the whole organ re 

 tractile into a low sheath with slightly sinuous margin. Color of the 

 rhinophores slightly darker than the mantle, thickly sprinkled with minute 

 dark spots. 



Branchial plumes 8 to 10, tripinnate, small, spreading, whitish yellow, 

 sprinkled with minute black spots. 



Total length of animal up to 30 mm.; width, up to 15 mm.; height, 

 to 6 mm. . 



Labial disc elliptical, convex, the labial armature of short, closely set rods 

 about 42 n long by 3.5 /x in diameter arranged in two yellowish lateral 

 lamellae nearly quadrangular in form on the upper half of the tube ; radula 

 colorless, twice as long as broad, not deeply grooved, the teeth in 20 rows 

 of 36 to 42 teeth in each half row ; rhachis naked, pleurse strongly hooked, 

 the innermost 20 to 25 in each row nearly equal in size, the hook slightly 

 increasing in length, the shaft obliquely curved toward the median line and 

 bearing a thin wing-like expansion on the inner side. The outermost 12 

 to 16 pleurse decrease very rapidly in size, fit closely together and become 

 reduced to thin concave plates. 



