DORIS. 



stomach at the anterior end, and curving upwards, passes obliquely backwards, towards the 

 right side, and to the nipple-formed anus (e) amidst the branchial plumes. 



The alimentary canal ofB.pilosa differs considerably from the above. In this species 

 the oesophagus, at its origin, is dilated, forming a large membranous sac or crop (PL 1, fig. 12/), 

 and is again enlarged {g) before it reaches the liver (h) : it then passes into that viscus, and 

 shortly afterwards receives the biliary secretion by three or four enormous openings (i). The 

 canal, now somewhat increased in diameter, and assuming the characters of a stomach (fig. 1 b, 

 and fig. 12/), emerges from the liver at its upper surface, and turning suddenly backwards, 

 passes in the form of intestine (fig. 1 c) along the right side of the back to the anus, situated 

 as usual. The stomach is internally minutely plicated, and has a small pancreatic sac (d) 

 attached to its pyloric extremity. 



The form of the alimentary canal in B. pilosa would appear to predominate in the genus. 

 In B. Johnstoni the type is the same, only the crop at the commencement of the oesophagus is 

 wanting. So it is with B. bilamellata, the crop being likewise deficient, unless the gizzard 

 opening into the buccal organ be considered as its homologue ; a view which we do not 

 consider probable. In this species, too, the enlargement of the oesophagus (fig. 1 3/), previous 

 to its entering the liver, has the walls of a glandular character. B. repanda, B. coccinea, 

 B. aspera, and B. depressa have all the alimentary canal constructed after the same plan. In 

 most, the inner surface of the stomach, and in all, the intestines, are longitudinally plicated. 



The liver is large (PI. 1, fig. 1 e, and fig. 2 d, d), filling the posterior part of the body ; it 

 is pyriform 3 the broad end, which is usually bilobed, being in front. The ducts from its 

 different portions converge towards one or more short, very wide trunks in the interior. 

 These open so immediately and largely into the stomach, that the alimentary matters cannot 

 fail of passing freely into them, as is the case in Eolis. 



The organs of the reproductive system (PI. 1, fig. 2e,f,g, h) are remarkable for their 

 large size, high development, and complicated arrangement, being of the usual hermaphrodite 

 character of the order. The intromittent organ (PI. 2, fig. 7 b) is of considerable size, and, 

 in its contracted state, lies in front immediately within the common orifice. The testis (c) is a 

 long, simple, convoluted tube, with the extremities connected, one with the penis at its base, 

 and the other with the oviduct at the sudden turn which that tube makes before entering" 

 into the channel of the mucus-gland, not far from the vulva, an arrangement identical with 

 that of Eolis. The ovarium (d) is spread over the liver, leaving generally a portion of the under 

 surface uncovered. The oviduct {e, e), passing from the anterior border of the liver-mass, 

 becomes suddenly dilated (/), and passes sinuously to the front of the mucus-gland, and then 

 turns abruptly backwards. Here (g) it receives the testis, as before stated, and immediately 

 afterwards sinks into the mucus-gland, and being joined by the duct (/) from the androgynous 

 apparatus, debouches into the female channel. 



The mucus-gland is a large, irregularly rounded, compressed mass, composed of two 

 parts ; one (/i, h) semi-pellucid and colourless, the other (i) opaque and reddish, the latter 

 being imbedded in the former ; both these parts are made up of the folds of a convoluted tube, 

 which in the opaque portion is very minute. This portion receives the oviduct, and both 

 parts of the glands communicate with a common channel (j), which is very short, and leads 

 to the external ovarian orifice. 



