1912. | H. J. FixurE: Anatomy of Melo indicus. 413 
organ were worked out as far as possible. A very definitely walled 
channel (Ant. V., pl. xxxii, fig. 16) coming from the anterior cavity 
of the animal (see above) runs just beneath the side of the external 
opening of the renal organ and, once arrived under the floor of 
the organ, it gives off branches as follows :— 
(a) A branch to the nephridial gland (N. G. V., pl. xxxii, 
fig. 16). 
(0) A branch to the left lobe (L.L.V., pl. xxxii, fig. 16). 
(c) A branch to the large part of the posterior or right lobe 
which lies morphologically in front of and topo- 
graphically to the right of the external aperture 
(ReolvaWer plo xexxit es 1:6); 
(d) A branch which goes along beneath the floor of the 
renal cavity and gives off branches to the several 
projecting lobes of the right lobe (R.L.V., pl. xxxii, 
fig. 16). 
The last-named blood channel appears to connect with the 
anterior visceral or abdominal sinus (A. Abd. S). The latter 
apparently also gathers blood from sinuses in the body wall and 
elsewhere around the renal organ, liver, etc. ; it is situated between 
the pericardium and the stomach and communicates with the 
afferent blood channel of the ctenidium. 
VII.—REPRODUCTIVE SYSTEM. (PI. xxxii, figs. 17—20). 
Both my specimens were females so I can only describe this 
sex and, in connection with it, I have mainly to confirm Haller’s 
results from Concholepas peruviana with some additional obser- 
vations. In other words, the genitalia are very similar in this sex 
for the two types. 
The ovary is composed of a number of long tubules spreading 
ovet the surface of that portion of the visceral mass which is 
occupied by the large posterior or right lobe of the kidney. The 
tubules form a branched system and lie side by side. As they 
unite they approach the posterior edge of the upper surface of 
this portion of the visceral mass and then bend round to its under 
(posterior) side in the lower part of which they open (after 
further uniting in pairs) into the common collecting duct which 
goes forward to open into the large oviduct. 
This collecting duct receives a duct from a large bladder-like 
structure which I shall call, tentatively at least, the albumen sac 
(Alb., pl. xxx, fig. 7). Itisin the position of the receptaculum semi- 
nis, so called at any rate, of Concholepas, but in the latter the col- 
lecting duct from the ovary seems to go into this organ and the 
channel to the uterus out from it again. The relations are there- 
fore not exactly the same, even if, as seems probable, the name 
receptaculum Seminis is an error. 
The oviduct is a large sac-like duct abutting on the posterior 
side of the branchial cavity narrowing down to a terminal duct- 
