1903.] OLIGOOH^TA FROM NEW ZEALAND. 209 



with the supra- intestinal vesseL As I have studied the specimen 

 only as an entire object, I cannot say anything as to the structure 

 of this organ, but it seems to resemble in its external features 

 the " blood-gland " which Beddard describes as occurring in seg- 

 ments xii., xiii. in P. suhterrcmeus. 



Dimensions. 15 mm. x| mm. It is much stouter than 

 P. lacustris, and consists of 70 segments. 



Locality. Lake Taupo, North Island, New Zealand. 



Taupodrilus, gen. nov. 



Taupodrilus simplex, sp. n. (Plate XXIY. figs. 1-9.) 



Of this worm I found about a dozen individuals, most of which 

 are only the anterior ends, and a few are entire. They are all much 

 coiled, rendering it a matter of some difificulty to make sagittal 

 sections. 



The following account is based on the study of three individuals, 

 more or less sexually mature, stained and mounted in Canada 

 balsam, and a series of longitudinal sections through the anterior 

 segments, and transverse sections of the middle region, in addition, 

 of course, to the usual glycerine and potash preparations. 



The prostomiu7n is conical and relatively long. 



Ghcetce. — The dorsal bundles consist of capilliform (at any rate 

 in the anterior segments), accompanied by bifurcate chpetse 

 (PI. XXIY. fig. 3), with a few delicate intermediate teeth. 

 Such chpetfe may be termed " multidentate " or " ctenate," and 

 occur also in Tuhifex rivulorum. 



The ventral bundle consists almost wholly of crochet-shaped 

 chsetse, with intermediate teeth. In the dorsal bundle there are 

 one or two capilliform and usually three or four ctenate chfetse 

 (in one individual the former were only present on segments v., vi., 

 vii. ; in another they did not begin till the fourth segment, and in 

 one specimen I was unable to detect them), and typically they 

 occur only on the first 12 to 15 cheetigerous segments. 



In the "ctenate" set the chief teeth or prongs are scarcely 

 curved (PI. XXIV. figs. 4, 4 a), and the number of intermediate 

 teeth varies from two or three to several ; usually they all separate, 

 but in a few instances a delicate striated membrane unites the chief 

 teeth as in " Psaminoryctes." The dorsal cheetse of segment ii. 

 are smaller than the rest. 



In the ventral bundle there are from 4 to 6 chsetse in the 

 anterior segments, diminishing to 3 or 4 in the mid-body. The 

 chief teeth are curved as in normal forked bristles or crochets ; 

 the upper tooth is less stout than the lower, and over the greater 

 part of the body the two teeth are of the same length, but in the 

 anterior segments the upper tooth is slightly the longer (PI. XXIY. 

 figs. 5, 6). Generally, all the crochets in a bundle have inter- 

 mediate teeth, which lie in a difierent plane from the main teeth ; 

 but in the anterior segments a minority in each bundle ai'e normal 

 crochets. 



Proc. Zool. Soc— 1903, Yol. II. No. XIY. 14 



