New Zealand Nematodes. 371 



in the male. In the female the rectum is one and one-half times 

 to two times as long as the anal body-diameter, while the pre- 

 rectum is nearly or quite three times as long as the rectum. In 

 the male the pre-rectum is about three-fourths as long as the neck. 

 Numerous glands are to be seen in the neighbourhood of the anus, 

 especially in the male. 



The lateral fields are about one-fifth as wide as the body. 



The inconspicuous nerve-ring surrounds the oesophagus rather 

 squarely. 



The tail of the female is concave-conoid in the anterior half 

 and setaceous in the posterior half, where it ends in an acute 

 terminus, destitute of opening or spinneret. The tail of the male 

 is obtusely conoid, and bears, near its extremity, at least two 

 slightly lateral papillae. The posterior extremity of the male is 

 invariably incurved. The anal region is not raised or made con- 

 spicuous by any special external markings or structures. 



From the large depressed vulva the vagina leads half-way 

 across the body where it branches into two symmetrical uteri 

 extending in opposite directions so as to occupy the middle third 

 of the body. Each ovary is reflexed and reaches about two-fifths 

 the way back to the vulva. As only immature females were seen 

 nothing is known about the eggs. 



•0 5;3 21-8 -M- 27 99-2 „ _„ 



•4 1-4 21 IT ^8 6 ' 36mm - 



is the formula of an adult male. 



External tactile supplementary sexual organs are present on 

 the males in the form of a row of ventral papillae arranged in 

 close juxtaposition. Taking the adjacent body-diameter as a 

 measuring unit, this row of papillae begins three measures from 

 the anus and extends two measures forwards. Each papilla is 

 innervated, and the total number is twenty -nine, the anterior one 

 being somewhat the largest. These papillae are most plainly to 

 be seen when the body is strongly incurved. There is no bursa. 

 The immediate region of the anus was not supplied with any con- 

 spicuous papillae. 



The two equal, plain, linear, arcuate, somewhat pointed spicula 

 were of the form usual to the genus and measured two and one- 

 half times as long as the anal body-diameter. Accessory pieces 

 were present. Powerful oblique copulatory muscles occupied part 

 of the space opposite the row of papillae. The two testicles were 

 straight and extended in opposite directions from a point a little 

 in front of the middle of the body, where they occupied a space 

 over one-quarter as long as the body. 



The species is a typical Dorylaimus of large size. 



Habitat, Lake Taupo, New Zealand, at a depth of 350 feet. 



