124 BULLETIN OF THE BUREAU OF FlSHERIEiS. 



Pharyngeal tube large, funnel-shaped, the large lip disc thickened and glandular, with rather 

 strong cuticula. In sections a dehcate armature of extremely fine short rodlets may be made out. 

 The pharyngeal tube is continuous into the pharyngeal bulb, with no sharp line of demarcation 

 externally. The latter is somewhat conical, strong, and about 2.5 mm. long, inclusive of the radula 

 sheath, which projects slightly behind. 



The radula is rather wide, colorless, the teeth in about 70 rows. The rhachis is narrow, naked, 

 the pleural teeth very numerous and slender, at least 70 to 100 in each half row, and of very striking 

 form, which readily marks out this genus from any other of the Dorididie. Each tooth is composed of a 

 slender shaft arising from a strongly compressed, triangular base of uniform or but slightly changing 

 size (pi. XVIII, figs. 25, 266); its distal end is slightly enlarged, slightly hollowed behind, and bears on 

 its thickened external and upper projecting margins a single series of extremely small denticulations, 

 which are continued down the outer border of the shaft for varying distances, in some cases reaching 

 i the length of the tooth (pi. xviii, iig. 26f()- The inner teeth are the longer, having a length of about 

 0.5 mm.; the outermost are much shorter, ranging down to 0.03 mm. The diameter of the shaft 

 averages 0.003 to 0.004 mm., increasing gradually toward the distal end, where it measures 0.006 mm. 

 to 0.008 mm. All the elements of the radula are very flexible, and the most careful manipulation is 

 nece.?sary to avoid bending and disarranging them. 



The short cesophagus passes directly backward to the stomach, which lies in the anterior cleft of 

 the liver. Its relations and those of the intestine are the usual ones in the Dorididse. The liver is 

 bluntly conical, the broader end directed forward with a deep median cleft occupied by the stomach. 

 Above the liver is slightly flattened and behind is bluntly rounded. Its length in a large individual 

 (16 mm. long) was 4.5 mm., with a greatest diameter of 3.5 mm. The right anterior lobe formed by 

 the median cleft is shorter than the left one and faceted by the pressure of the anterior genital mass. 



The ovotestis is a lobulated organ closely attached to the dorsal and anterior surfaces of the liver. 

 In thickness it is nearly equal to the latter organ and thus makes up at least one-halt of the bulk of 

 the two. From the inner face of its left lobe the hermaphrodite duct is given off, passing immediately 

 below the pyloric end of the intestine downward and to the right, in front of the le-ser (anterior) curva- 

 ture of the stomach, thence obliquely forward beneath the spermatotheca to dilate into the herma- 

 phroditic ampulla. It is much larger than in Dorididse of similar dimensions, reaching a diameter of 

 0.3 mm. The hermaphroditic ampulla is very large, its average diameter beingabout 0.7 mm., with a 

 total length of about 6 mm. It is coiled in an S-shaped loop upon the lower anterior face of the ante- 

 rior genital mass (pi. xxi, fig. 112, h. amp. ). At its anterior end it constricts suddenly, gives off the 

 narrow spermatic duct and passes into the nidamental gland. The spermatic duct is very short, dilat- 

 ing into the large thick-walled prostata, which describes a U-shaped loop upon the upper anterior face 

 of the anterior genital mass, immediately above the hermaphroditic ampulla, and resting upon and 

 against the spermatotheca (pi. xxi, fig. 112, pr.). Its distal end constricts into the muscular vas defer- 

 ens, which describes a downward loop, returns and passes outward to dilate gradually into the penis 

 (pi. XXI, fig. 112, ('. d.). The glans penis is cylindrical, blunt, about 3 mm. long by 0.04 mm. in diame- 

 ter, is covered with a firm cuticle and with 5-6 rows of small recurved hooks (pi. xxi, tig. 114) . These 

 hooks average 0.003 mm. in height and 0.005 mm. in length. 



The vagina is conical in form, its greatest diameter about 0.4 mm., its length 0.6 mm., and passes 

 rather abruptly into the vaginal duct, a slender, thin-walled tube which courses straight inward to 

 the spermatotheca, into which it opens very close to the exit of the uterine duct. 



The spermatotheca is a large spherical thin-walled organ, having a diameter of about 2 mm., and 

 making up fully one-third of the volume of the anterior genital mass (pi. x.xi, fig. 112, sp. th.). Into 

 the uterine duct, close to its origin, opens the narrow, slender duct of the spermatocyst, a rather large, 

 elongated, pear-shaped organ lying upon the groove between the spermatotheca and the nidamental 

 gland and overlapping both organs. Its distal end curves outward, is doubled downward upon itself 

 and is continued into a short duct which opens into the uterine duct of the spermatotheca, close to the 

 latter. The total length of the spermatocyst is about 2 mm., its greatest diameter being nearly 

 0.5 mm. 



The nidamental and albumin glands make up about one-third the bulk of the anterior genital 

 mass. The former is much the larger, contains a large cavity and partially incloses the albumin 

 gland on its inner face. The duct of the nidamental gland (pi. xxi, figs. 112, n. gl. d.) lies below and 

 slightly behind the vas deferens and vaginal duct, their external openings occupying a similar 

 relation. 



