REPORT ON THE NUDIBRANCHIATA. 
89 
The thin, whitish duct of the hermaphrodite gland issues on the upper side of the cardia, 
and runs obliquely downwards to the anterior genital mass. The latter is iarge, 14 ’5 mm. 
long by 7 ’5 mm. broad, and 9 mm. high, yellowish-white, thicker before, tapering behind, 
the right side arched, the left side convex before and slightly hollowed out behind ; the 
principal efferent ducts projecting 3 mm. The ampulla of the hermaphrodite duct is 
yellow, lying on the middle of the left side ; it forms a few curves, and when extended is 
nearly 1 cm. long, and measures almost 1 mm. in diameter. The male branch of the ampulla 
is attached for a length of nearly U5 mm., and then passes into the spermatic duct, which 
forms several long loops, measuring when extended nearly 3 '3 cm. by - 5 mm., in diameter, 
and winding on the front and on the inner side of the genital mass. Below the spermatic 
duct (fig. 12, a) becomes somewhat dilated, and forms the penis (prseputium) (fig. 12, b), 
nearly 2 mm.' long, the upper half of which is filled with the conical unarmed glans. 
Upon the anterior end of the genital mass lies the spherical, yellowish sperma- 
theca (fig. 11, a), nearly 3 ‘5 mm. in diameter, filled with sperma and detritus. The 
vaginal duct (fig. 11, b) is rather strong, running almost straight, nearly 7 mm. long 
by nearly • 75 mm. in diameter; the inner side with strong, mostly pinnate folds. 
The uterine duct rises nearer the vaginal (fig. 11, de), but is rather longer, about as 
thick as the last, but narrowed below, and opening near the root of the duct of the 
mucous gland. The spermatocyst is attached to the base of the uterine duct (fig. 11, c ) ; 
it is also yellowish- white, sac-shaped, somewhat bent, measuring when extended 4 - 3 mm. 
in length, and swollen with spermatozoa. The mucous gland is very large, forming by 
far the largest part of the genital mass ; its cavity was wide but empty ; the albumini- 
parous gland, which projected in front on the left side, was yellower ; the duct of the 
mucous gland had the usual fold. A vulvo-vaginal gland was not found. 
2. Archidoris australis, n. sp. (PI. I. figs. 13-18; PI. II. fig. 13 )j 
Habitat . — Indo-Australian Ocean, Kerguelen Islands. 
There was only a single individual of this species, taken off Howe’s Foreland, 
Kerguelen Island, January 27, 1874, at a depth of 95 fathoms. 
This specimen, which was well-preserved in spirit, was 15 '5 mm. long by 8’ 5 mm. 
broad and 6 mm. high ; the breadth of the mantle-border came to 3 mm., the breadth 
of the foot to 4‘5 mm., the length of the tail to 2'6 mm., the height of the (retracted) 
rhinophores to 2 mm., of the extended gill nearly to 2 mm. The colour of the back 
was yellowish with touches of faint green ; that of the lower side of the mantle-border 
whitish, of the foot yellowish- white ; the rhinophores and the gill of the same colour as 
the back. 
The dorm is oval, the consistence as above. The bach is entirely and pretty thickly 
(ZOOL. CHALL. EXP. PART XXVI. 1884.) Cc 12 
