OPISTHOBRANCHIATE MOLLXJSCA FROM MONTEREY BAY. 117 



bulb, is oval in ^'eneral outline, the broader, thicker portion directed posteriorly. Length about 5 

 ram., width 4 mm. The posterior gland is transversely placed immediately behind the cerebral gan- 

 glia, extending on the right over a part of the anterior genital mass. Length 5 mm., width 6 mm. 



Pharyngeal bulb large, conical, its length about 10 ram., width 8 mm., and height 6 mm., the 

 radula sac projecting behind and below as a rounded cylindrical process of 4 mm. length. Lip disk 

 .1 mm. in diameter, covered with a thick colorless cuticula, the opening an inverted T-shaped cleft. 



Radula broad and short, deeply grooved, colorless or nearly so, the rhachis very narrow, naked. 

 Teeth in 26 rows, the last 2 being immature. Pleural teeth large, stronglj' hooked, 55 in anterior 

 rows, 60 in the iniddle rows, and 62 in the posterior rows. The general type of the pleural teeth is 

 much the same as in Archidoris, the outer face being more convex than the inner. The outermost 

 teeth increase rapidly in size toward the center of the row (pi. xviii, fig. 7), the shaft and hook being 

 nearly at right angles. The teeth from the middle portion of the row (pi. .win, figs. 8 and 11) have 

 strongly curved hooks, much more so than in ArchidorU montereyensis (cf. pi. xviu, fig. 3), while the 

 wing-like expansion along the inner margin of the shaft is but slightly developed. The innermost 

 pleural teeth (pi. .xviii, figs. 9-10) decrease slightly in size, possess strong, curved hooks, strongly 

 convex outer and concave inner and dorsal surfaces of the shafts. 



Salivary glands long, narrow, band-like, passing backward near median line on floor of the body 

 cavity beneath the stomach, with a total length of 15 mm. and a width of 2 mm. at anterior end and 

 gradually narrowing posteriorly. 



The thin-walled cesophagus leads directly backward to the large S-shaped stomach lying in a 

 broad notch in the anterior end of the liver, its cardiac end below and in median line. The organ 

 curves upward and to the left, its pyloric end passing obliquely forward to the right side into the 

 intestine, receiving the broad bile duct on the posterior lower surface near the cardiac end. Length, 

 about 24 mm., greatest diameter about 8 mm., these dimensions varying with the degree of distension. 

 The intestine is a stout tube about 3 mm. in diameter at its origin from the pylorus, curving upward 

 and diagonally backward from left to right in front of the stomach, and coursing backward in a deep 

 groove on the dorsal surface of the visceral mass at the right of the median line to the anal papilla, 

 in the center of the circle of branchiae. Total length about 40 mm., its inner surface longitudinally 

 plicate. The liver is bluntly conical in shape, yellowish, closely covered by the hermaphrodite gland, 

 its apex directed posteriorly. In front is a deep wide cleft occupied by the stomach, above a dorso- 

 lateral longitudinal groove for the intestine, the right anterior lobe flattened into facets by the pressure 

 of the anterior genital mass. 



The hermaphroditic gland is yellowish, thin, closely invests the liver, and at its anterior upper 

 border gives origin to the short, narrow, straight hermaphroditic duct, 2 mm. long by 0.3 mm. wide, 

 which pajsses directly forward to the anterior genital mass, dilating into its wide, whitish ampulla, 

 which is closely looped upon the inner anterior face of the mass. The diameter of the hermaphroditic 

 ampulla is 1 mm., its length about 8 mm. 



The anterior genital mass is large, its outer surface convex, its inner rounded in front and beveled 

 obliquely from within outward behind. .\t its anterior inner margin the distal end of the hermaph- 

 roditic ami)ulla passes into the substance of the nidamental gland and divides into the spermatic duct 

 and the oviduct. The former duct is short and narrow, passing almost at once into the large, whitish 

 yellow prostate gland which lies upon the upper surface of the anterior genital mass. It is a large 

 ovoidal liody, with smooth outline, about 6 mm. long by 3 mm. in greatest diameter, convex above and 

 flattened below. From its distal extremity passes the long, slender vas deferens, about 22 mm. in 

 length by 0.6 ram. in greatest diameter, convoluted into a number of close loops along the anterior 

 liorder of the genital mass, and dilating into the thick, conical penis (prseputium), which is 2.4 mm. 

 wide by 4 mm. long (retracted), with a short, conical, miarmed glans. 



The uterine duct receives the duct of the spermatocyst a short distance from its point of emergence 

 from the nidamental gland. The spermatocyst is spherical, 1.5 ram. in diameter, with a short duct about 

 as long as the cyst. The large spherical grey spennatotheca, 5 mm. in diameter, is situated in the 

 posterior half of the anterior gertital mass, and receives the oviduct on its lower anterior surface close 

 to the point of origin of the vaginal duct. The latter is about 10 mm. long and 0.3 mm. in diameter, 

 dilating gradually at its distal end into the unarmed vagina. The nidamental and albumin glands are 

 large, their structure and relations usually as in the Archidoridinje. 



