REPOET OR THE NUDIBRAH CHIATA. 
151 
evaginated as a low papilla armed with hooks. The whole armed portion of the vas 
deferens was about 3 mm. long, by about '08 in diameter, increasing to ‘1 mm. on the point. 
The number of the longitudinal rows of hooks towards the point was twenty-five, arranged 
quincuneially ; farther back there were twelve to fifteen; 1 in a single row I counted 
about 170 hooks. The hooks are yellow coloured, slightly bent, the hindermost being 
•02 mm. long ; 2 their form and structure as usual. The retractor muscle of the penis is 
much as usual, but rather longer, as Semper 3 has already stated. The dart-gland is a 
large yellowish coil of about 4 mm. in diameter; unrolled, its length was 10 cm. by about 
•5 mm. in breadth; its lumen and structure are as usual. The gland gradually passes into 
the ampulla, which was of an elongated spindle shape, and measured 7 mm. in length by 
•8 mm. in diameter ; its very narrow cavity is roundish in section, the structure being as 
usual. The duct of this gland is a little longer than the ampulla, and a little thicker than 
the gland, with strong walls (fig. 11, d). The dart-sac is elongated-conical, slightly bent, and 
7 - 5 mm. long, with a diameter of *9 mm. posteriorly, and 2 mm. in front ; its anterior end, 
like the anterior margin of the prseputium, is black. The inside of the thick walls shows 
strong transverse folds above, and slight longitudinal ones beneath ; behind, quite at the 
base of the sac, is the depressed dart-cone (fig. 11, a), in the cavity of which is the dart 
(fig. 11, h), the darker basal portion of which (fig. 11, c) is visible through the walls of the 
sac. The dart 4 is straight, pale yellowish in colour, dirty brownish-yellow at the root ; 
its length is 1’76 mm., and diameter '03 mm. at the apex, T6 mm. at the base; the 
aperture (fig. 12, a) at the apex is in form nearly like that of the previous species — 
circular ; the walls of the dart contain the usual cells, especially towards the apex 
(fig. 12), where they are also larger. The retractor and protrusor muscles of the dart-sac 
are as usual. 
About half (l mm.), of the white foot gland (fig. 8, h) projected freely in the middle 
line ; the gland is somewhat more flattened than in the previous species, the cavity 
extends through the entire length of the gland ; the duct is generally as long as the 
gland itself, and opens by a narrow slit ; just in front of the opening is the end of the 
genital furrow. 
1 Semper (loc. cit., p. 257) gires the number of “ cartilaginous teeth ’ in the “ rings ” as twenty or more in front. 
2 According to Semper (loc. cit., p. 257) the height is - 02 to '07. 3 Loc. cit., p. 259. 
4 Semper has already (loc. cit., Taf. xxii. fig. 3) figured the dart. 
