220 PROF. W. B. BENHAM 0:!<r AQUATIC [ISToV. 3, 



collected in Lake Taupo, and clearly belong to the genus 

 Enchytroius. 



The prostomium is short, rounded, and somewhat conical ; the 

 anterior segments are well marked, though the body- wall is thin 

 and transparent. 



The chcetce are in four bundles, of (usually) three in each bundle ; 

 they are straight rods with blunt ends ; all are alike in form 

 and size. The three chsetse in each bundle are arranged fanwise, 

 i. e., the middle one upright, and the other two making equal 

 angles with it on either side. Occasionally, in the anterior ventral 

 bundles, a fourth ch^ta was noted. 



The clitellum covers segments xii., xiii., and part of xiv. 



The malepores, on segment xii., are in depressions on either side 

 and in line with the ventral series of chpetse, which, however, are 

 absent in this segment. 



hiternal Anatomy. 



The brain is convex posteriorly. Peptonephiidia are absent 

 from the back of the pharynx. 



The ordinary nephridhm% has a relatively long and narrow pre- 

 septal region (PL XXYI. fig. 26) ; the postseptal i-egion is about 

 twice the length of this, and is distinctly marked off from it. 

 It consists of an u^regulai'ly pear-shaped " body," which tapers off 

 posteriorly to form a long narrow duct, set nearly at right angles 

 to the "body," but slightly inclined forwards. 



The spermiducal funnel is particularly large (PI. XXYI. fig. 28), 

 about four times as long as its breadth ; it is thick, and bent in 

 moi'e than a U-shaped curve (perhaps due to changes during 

 preservation), for it appears S-shaped in longitudinal section. The 

 entrance is narrow, but there are no columnar cells at its margin, 

 which is not reflexed. The v/all of the whole funnel consists of 

 long glandular cells, which in their distal moities are filled 

 with granules. 



The sperm-duct is short, confined to its segment, and coiled in 

 a close and regular zigzag ; it opens in a depression which results 

 from the contraction of several radiating muscles in this region, 

 near a group of gland-cells which open through the epidermis on 

 the outer side of the male pore. 



The spermatheca (PI. XXYI. fig. 27), which communicates with 

 the ojsophagus, lies in the usual segment. The ampulla is nearly 

 spherical ; the duct is distinctly marked off from it, is about half 

 the length of the ampulla and much narrower than it. 



Gland-cells are present around the duct throughout its length ; 

 that is, the epithelium consists of tall cells with clear contents ; 

 the greater part of each cell projects beyond the muscular wall of 

 the duct, and these portions form a continuous extra-muscular 

 layer (PI. XXYI. fig. 28). The actual lining of the duct appears 

 to be formed by a protoplasmic sheet, in which I detect neither 

 cell-boundaries nor nuclei ; and this sheet appears to result from 

 the fusion of the internal ends of these " glandular " cells. The 



