86 Memoirs of the Indian Museum. [Voiv. I, 



which is situated on the lower surface of the telson close to its junction with the last 

 abdominal segment. With the exception of the last fifteen millimetres of its length, 

 the hind gut of the specimen examined was flattened horizontally to such an extent, 

 that its upper and lower walls were in close contact throughout, and the lumen in 

 transverse section appeared as a horizontal line. The breadth of this flattened organ 

 was about 20 mm. in the anterior half, but it gradually became less behind. Near 

 the telson it becomes much narrower; and about 15 millimetres from the anus 

 the horizontal position of the linear lumen becomes vertical. Anteriorly, the wall of 

 the hind gut is very thin and its mucous membrane is thrown into delicate folds 

 arranged in a reticular manner: it becomes thicker behind, owing mainly to an increase 

 in the longitudinal muscle fibres. Near the anus, where the lumen is vertical, it is lined 

 by thick, smooth, yellow cuticle, the opposing surfaces of which are in close contact, 

 so as to retain the intestinal contents. 



Hepatopancreas. 



In Bathynomus this organ is quite different from that of other Isopods, so far 

 as they are known. It consists of three pairs of elongated glandular organs 

 (pi. X, fig. i) or six separate lobes, each of a simple racemose type. In the spirit 

 specimen, they can be distinguished at once from the other contents of the thorax by 

 their reddish brown colour. The six lobes are situated alongside of the mid gut. 

 They are of about the same size ; each, m.easuring 40 mm., in length and 7 mm. 

 in thickness, extends from the posterior part of the first segment to the lower 

 border of the third. The outer surface of each lobe is covered with small granulations, 

 the outward expressions of the short tubules of which the organ is composed. 

 From near the anterior end of the highest pair, small ducts are given off which open 

 into the mid gut close to its union with the gizzard. The lowest pair lie wholly be- 

 neath the mid gut in close contact with one another, and are therefore not shown in the 

 figure. The ducts of the middle and lower lobes were not traced, owing to difficulties 

 arising from the presence of yoke material. They probably open by separate ducts 

 into the mid gut, in the same way as the ducts of the highest pair of lobes. 



The salivary glands. 



Situated on either side of the pharynx are two small bodies of soft, friable consis- 

 tency. On microscopical examination these bodies are seen to be racemose glands. 

 When examined in section, they show at first sight a remarkable resemblance to the 

 salivary gland or pancreas of a vertebrate animal. These organs, which are shown in 

 pi. xi, fig. 2, measure about 4 mm. in length and 2 mm. in breadth. Beneath them is 

 the cuticle, between the mouth and the base of the mandible : in front, they are in 

 contact with a dilator muscle of the pharynx d.p. : internally, they touch the side wall 

 of the pharynx at its lowest part. The duct or ducts of these organs were not traced ; 

 though it may be stated, that in all probability they do not open into the pharynx, 

 for the following reason : Before the gland of one side was dissected it was gently 

 separated from the pharynx, while light was transmitted through the cuticle from 



