372 Mr Cobb, On Free-living fresh-water 



Dorylaimus profundis, n. sp. 



•0 5-9 22- '50-' 84 98-2 

 •5 1-8 2-3 2-8 1- 



mm. 



is the formula of a female that, though having the appearance of 

 being full grown, had not yet produced eggs. The structure of 

 the skin was entirely typical, and so closely resembled that of 

 Novae Zealandiae that the same description would apply to both, 

 and it may be here remarked that in spite of the marked differences 

 pointed out later on, the two species resemble each other out- 

 wardly in a marked degree. 



The conoid neck becomes convex-conoid at the head end, 

 where there is a distinct lip region, which though presenting the 

 same contour as that of Novae Zealandiae is of quite a different 

 character. In speaking of Dorylaimus latus in Vol. VI. (1891) of 

 the Proceedings of the Linnaean Society of N. S. W.I described the 

 manner in which the lip region of that species can be protruded, 

 and gave a figure of the protruded condition of the lips. It 

 seems that the head of D. profundis has a similar structure. In 

 the present case I have not seen the lips protruded, but the chitin 

 at the head presents that infolding characteristic of the head of 

 latus and some other species. This structure of the head together 

 with differences in the structure of the posterior extremity enable 

 one to distinguish readily between the two species Novae Zea- 

 landiae and profundis. 



As usual there are six obscure lips each bearing a single almost 

 invisible papilla. 



There is nothing striking about the structure of the pharynx, 

 the stout spear sliding in a ring located behind the infolded lips at 

 a distance one and one-half times as great as the width of the head. 



The oesophagus is simply conoid, being anteriorly one-third 

 and posteriorly one-half as wide as the corresponding part of the 

 neck. The lining is plainly to be seen in the posterior part. 

 The oesophagus, is set off from the intestine by a prominent 

 constriction. 



The dark coloured intestine is one-half as wide as the body 

 and is composed of cells presenting a tessellated arrangement. 

 In the female the pre-rectum is one-third to one-half as long as 

 the neck, while in the male it is much longer, namely somewhat 

 longer than the neck. 



There seems to be no gland emptying ventrally as in many 

 Nematode genera, but certain organs, apparently glandular, are 

 to be seen in the neck region and these probably debouch 

 laterally. 



The lateral fields are one-third to one-fourth as wide as the 

 body. The nerve-ring encircles the oesophagus rather squarely. 



