96 Records of the Indian Miisetnu. [Vor,. IX, 



vary slightly accordingly to the degree of contraction during pre- 

 servation. The ventral surface is slightly concave and the dorsal 

 surface convex. The curvature is usually greatest towards the 

 anterior extremity. At this extremity there is placed terminally, 

 a slightly muscular sucker, '4 mm. in diameter, at the base of 

 which the mouth is situated. Owing to the curvature of the 

 animal this sucker appears subventral rather than terminal. On 

 the ventral surface, anteriorly, there is a second larger and more 

 muscular sucker, having a diameter of '6 to 7 mm. and situated so 

 that the centre of the sucker lies midway between the two super- 

 ficial divisions of the body. Granular depositions occur in the skin. 

 Anteriorly these are arranged in discontinuous concentric bands, 

 whilst more posteriorly they become irregular, and are often con- 

 centrated at the lateral margins. The digestive apparatus repre- 

 sents all that is developed of the internal anatomy. As we have 

 seen, the mouth is situated at the base of the anterior sucker. It 

 leads into an extremely short oesophagus, and this divides immedi- 

 ately into the gut, which consists of two simple undivided branches 

 running along the sides of the animal to the extreme posterior end. 

 No pharynx was present. The two lateral branches, or rami, of the 

 intestine are discernible to the naked eye, as broad thickened 

 patches of a yellow colour, forming nearly the entire body of the 

 animal. Under magnification, the walls of the intestine are seen to 

 be puckered. Posteriorly, the two branches terminate blindly. No 

 trace of either the reproductive or excretory system was discern- 

 ible even under high magnification. 



This species, which being immature, cannot at present be 

 determined, bears a general resemblance to an immature Distonium 

 obtained and figured by Linton (i) from two species of Dolphin, 

 VIZ. Corypliacna hippurus and Coryphaena cquisetis, common in 

 American waters. He refers to this parasite (without naming it) 

 as under : — 



''Dimensions in millimeters, slightly compressed. Length 3-35. 

 Diameter anterior q-ii, at ventral sucker 0*33, nearly uniform to 

 posterior end. Oral sucker o'lo, breadth o-qS, ventral sucker 

 circular 0-24 in diameter. These specimens are immature. There 

 is no pharynx. The oesophagus is slender. The intestinal rami 

 begin in a convoluted mass slightly in front of ventral sucker, and 

 continue to the posterior end, being voluminous and apparently 

 irregularly constricted, so as to present the appearance of a series 

 of translucent bodies filling the post-acetabular region of the 

 body. The intestines are filled with structureless seemingly colloid 

 rnaterial. No trace of genitalia could be made out in any of these 

 distomes. While they are immature there should be no difficulty 

 experienced in recognizing these pecuUar forms." 



Our species thus differs from Linton's in being much broader 

 and in having larger suckers. His were marine, ours are fresh- 

 water. Young forms of different species are, in all probability, very 

 similar. It seems likely that in spite of the general resemblance 

 of Linton's species to ours, they are different. The occurrence of 



