120 BULLETIN OF THE BUREAU OF FISHERIES. 



the back sprinkled everywhere with minute brown and black spots between the papillae. The num- 

 ber of these spots is highly variable, in some individuals being very small, in others thickly set and 

 often grouped in small patches, deepening the general color of the animal to a reddish bmvvn. hi 

 alcohol the red color is quickly lost, the more permanent brown becoming very conspicuous u|>oii tin- 

 light yellowish white of the rest of the animal. 



Dimensions of largest individual taken, IS mm. in length, 10 mm. breadth, .5.5 mm. height, tin- 

 average size usually found, however, being about 8-12 mm. long. 



Dorsum covered everywhere with small, closely set, hispid papillse, in height ranging up to 0.42 mm . 

 ill diameter to 0.08 mm., strengthened by divergent spicules extending from base to apex, the central 

 portion of apex sunken and surrounded by the higher margin, elevated at intervals by the spicules 

 into pointed projections. 



Sides of foot nearly parallel, abruptly rounded in front, more tapering behind. Anterior margin 

 deeply bilabiate (pi. xxi, fig. 109), the upper lip projecting beyond the lower, notched in the median 

 line. Oral tentacles long and slender. General color of the ventral surface of foot, mantle, and sides 

 of body a lighter red than the dorsum, rarely with fine black sprinklings. 



Rhinophores (pi. xxiv, fig. 8) short, stout, translucent pink, the stalk stout and conical, prolonged 

 above the clavus as a blunt, cylindrical process, nearly one-fourth the length of the whole organ. C'la- 

 vus perfoliate, bearing altogether from 20-24 nearly vertical leaves (10-12 on each side). The leaves 

 rather thick, triangular, with the apex directed downward, increasing in size regularly from liefore 

 backward. Tip of rhinophore directed forward, the rest of the organ nearly vertical. Rhinophore 

 entirely retractile within sheath, the margin of which is not appreciably elevated above the sur- 

 rounding dorsum, and bears papillae similar to those of the general donsal surface. 



Branchial plumes 10-12, erect, separate, nearly equal in size, slightly paler than dorsum, arranged 

 in a circle, completely retractile within a sheath the margin of which is scarcely elevated and bears 

 papillie similar to those of the dorsum. Anal opening upon a low papilla in the center of the circle 

 of branchiie, the minute renal opening at its right and slightly in front. 



Labial disk round, convex, covered with thick colorless cuticula, its opening j. shaped. The 

 lower half of the sides of the opening is occupied by a crescentic band of flattened hooks, the slightly 

 concave border being directed forw-ard, the upper angle much in advance of the lower, the lower ends 

 being separated by a narrow space. Length of the armature, 0.24 mm. ; its greatest width, 0.072 mm. 

 The elements of the armature are arranged in 5 rows closely overlapping each other, their general 

 shape being the same. The hooks of the most anterior row are blunt, flattened, and but slightly 

 elevated and directed forward, the base rounded in front, the upper surface sloping backward beneath 

 the hooks of the succeeding row. The elements of the remaining rows progressively decrease in size, 

 the hcMjks are shorter and pointed. Length of longest element of the most anterior row, 21 //; its 

 width 6 //, decreasing in the last row to a length of 6 /(, and a width of 5 fi (pi. xviii, fig. 21). 



Radula broad, colorless, the median groove deep. Teeth in 65-80 rows, with 81 teeth in each 

 row. Rhachis naked. 



First pleural tooth thick, stout, the base short and broad, its hook heavy, slightly curved with 8-11 

 small denticles upon its inner margin (pi. xviii, fig. 18a). Height of base to ape-x of hook about 

 0,013 mm., the length of hook 0.008 mm. The succeeding 10 pleural teeth have a large, strong, broad 

 base bearing a wing-like expansion thickened above upon its outer border, overlapping the adjacent 

 tooth (pi. XVIII, fig. 19). The hookis strong and thick, increasing in length and becoming more slender 

 from about the twelfth tooth outward, the base diminishing in size, the hook longer, more slender, 

 and less curved (pi. xviii, fig. 20a), passing over rather rapidly into long, slender elements (pi. xviii, fig. 

 206, e), each w-ith a small, compressed, wing-like base and long, slender, slightly curved hook, bearing 

 at the distal end from 1 to 6 very long denticles upon the inner margin. These denticles arise in the 

 distal third of the hook and, increasing slightly from within outward, reach nearly to the tip of the 

 tooth and give it the appearance of being divided (pi. xviii, fig. 20c-/). The outer teeth of the rows are 

 very flexible and slender, thus giving to this portion of the radula a brush-like appearance. 



The hermaphrodite gland extends over the dorsal, lateral, and anterior faces of the liver as a thin 

 layer, varying from 0.18 mm. to 0.3 mm. in thickness, being at its maximum about one-third the 

 thickness of the liver in the same section. From its right anterior lobe arises the very narrow^ and 

 short duct which extends obliquely forward and downward to the hermaphroditic ampulla. The 

 anterior genital mass 'S large, being at least half as large as the hermaphrodite gland and li\er com- 



