60; DR. H. LYSTER JAMESON AND DR. W. NICOLL ON 



ventral sucker. It seems to form a single loop, starting from the 

 ovary, passing behind the ventral sucker and- up along the left . 

 side of the body to some distance in front of the sucker, then 

 retui'iiing in the same way. The eggs are of conspicuously large 

 size, measuring •021--028x -OIS-OIS mm. 



There were a considerable number of much smaller specimens. 

 (•13-'19 mm. in length) bearing a close resemblance to the fore- 

 going. Even the smallest of them, measuring only "135 mm. 

 in length, was fully mature and contained about a dozen large 

 eggs. All intermediate sizes between this and "2 mm. were 

 observed. It is difficult to decide whether these small specimens 

 are the same as GymnophaUus affinis or whether they represent 

 a distinct species. The dift'erences, apart from the difierence 

 in size, are not very easy to detect. The body is altogether more 

 plump and the various organs more packed together. The 

 suckers are relatively larger. The intestinal diverticula extend 

 past the middle of the body and are in contact with the ovary 

 and the vesicula seminalis. The yolk-glands are slightly further 

 back and appear to be partly fused or at any rate very close 

 together, while the uterus extends forwards to the oral suckers 

 on the left side. These differences, although noticeable, do not 

 appear sufficiently constant to warrant the creation of a further 

 new species, so that for the present we shall content ourselves 

 with noting the existence of these smaller forms. 



Gymnophallus macroporus, sp. n. (Text-fig. 12.) 



This is the largest of the four species, and measures •4-"5 mm. 

 in length by '14-" 2 3 m.m. in maximum breadth. The greatest 

 breadth is across the middle of the body, but is not very much 

 greater than that of the oral sucker, and this gives the animal 

 a very characteristic shape. The lips of the sucker ai'e usually 

 everted and project well beyond the sides of the body. From 

 the anterior end the body tapers gradually towards the pointed 

 tail, though there is usually a slight inflation a little in front 

 of the ventral sucker. The oral sucker has a transverse diameter 

 of •14-'17 mm., the ventral sucker •065-*075 mm. The ratio 

 is generally about 9 : 4. The ventral sucker is situated at a 

 distance of about •3-'4 mm. from the anterior end of the body, 

 i. e. about three-fourths of body-length. 



Almost contiguous with the oral sucker is a comparatively 

 large pharynx measuring "040 x '035 mm. The oesophagus is 

 slightly longer than the pharynx, measuring '05 mm. The 

 intestinal diverticula are usually moderately distended and form 

 an acute angle with each other. Their ends reach well past the 

 middle of the body. 



The excretory vesicle is V-shaped and the limbs are frequently 

 enormously distended, compressing the intestine and giving the 

 anterior part of the body a hollow appearance. 



Owing to the close packing together of the eggs the ovary and 

 testes were extremely difficult to discern. They appear, however. 



