MESSRS. HANCOCK AND EMBLETON ON THE ANATOMY OF DORIS. 219 
same minute size. The androgynous apparatus is modified in this species in the 
following way : the vagina and the channel, from the principal spermatheca to the 
oviduct, are united and communicate with that bag as a single tube ; the channel to 
the oviduct is of considerable calibre, tortuous, and is continued into a blind dilated 
pouch, from the side of which comes off a short duct leading direct to the oviduct. 
The caecum here mentioned may be regarded perhaps as an accessory spermatheca ; 
it, as well as a portion of the dilated tube leading into it, is imbedded in the mucus> 
gland, which is not the case with the corresponding parts of D. tuherculata. 
In T). pilosa the testis is shorter than in the last species, and somewhat stouter, 
but otherwise as in D. tiihercidata. The vagina is very long and wide, and before 
reaching the spermatheca becomes constricted into a very fine tube, which a little 
before its entrance into the principal spermatheca, has appended to it a small acces- 
sory pouch with a delicate duct ; between the junction of this duct and the principal 
spermatheca, and quite close to the latter, a very fine channel passes off nearly at 
right angles to join the oviduct at the usual point. 
B. repanda^ has the testis reduced to a very short but wide tube, abruptly con- 
stricted at each end ; at the outer end succeeds a narrow duct of nearly the same length 
as the testis itself, leading to the penis ; this duct may be compared to the vas deferens. 
At the inner end, the constriction is in close contiguity to the junction of the testis 
with the bent part of the oviduct. The dilated portion of the oviduct is longer and 
wider than usual, and is suddenly constricted in front as in D. bilamellata ; but in 
B. repanda, in which all these parts are remarkably open to observation, this con- 
stricted part of the oviduct is only once bent upon itself, where it is joined by the 
testis; a little further on it receives at another simple bend the channel from the 
androgynous apparatus, and as a smalt duct may be seen to enter the mucus-gland. 
The vagina is short, and soon receives a duct from the principal spermatheca ; the 
tube then bends upon itself, becomes somewhat convoluted, and runs to terminate in 
the accessory spermatheca; the channel to the oviduct being given off as a very 
fine duct from the convoluted part, a little way in front of this last receptacle. The 
spermathecm are more nearly of a size than in previous examples, and are both 
globular. The mucus-gland is here formed of the convolutions of a much larger 
tube than in any of the before mentioned species. 
Hitherto we have noticed those species which possess a single loosely convoluted 
and comparatively short tube, which alone we have considered testis. We have now 
to call attention to another set of species, which are provided over and above with a 
dense fusiform mass bent upon itself, composed entirely of a very fine convoluted 
tube, the coils of which are compactly cemented together, forming a concentrated 
gland enclosed within a fine capsule. 
Of this seeond set, B. tubercidatadp, Verany, is here first noticed, as it will lead us 
naturally to the rest; it has both the loosely convoluted tube and the fusiform gland 
* Plate XV. fig. 5. t Plate XV. fig. 4. 
