1903.] OLIGOCH.ETA FROM NEW ZEALAND. 207 



and immature specimens of Tahifex sp. and of LiinnodriluSy 

 amongst which some appear to be L. vejdovskycmus. 



Lake Waikare, North Island. 



Greatest depth 9 feet. Only one haul was taken, which 3delded 

 numerous specimens of Limnodrilus vejdovskyanus and one 

 individual of Tcmpodrilus simplex. 



It will thus be seen that the lakes in the North and South Island 

 respectively differ considerably in their Oligocha^tes, so far as 

 research has yet gone. 



The two species of Fhreodrilas are very distinct, one confined to 

 the north, and the other evidently common in the southern lakes. 



Of Taupodrihis, the noi-thern and southern representatives may 

 be distinct, though I have included them in the same species, as 

 the southern material was not in sufficiently good condition to 

 permit me fully to investigate the details of the reproductive 

 organ. 



Unfortunately the southern representatives of Limnodrilus are 

 immature, but they appear to differ in the form of their chfetse 

 from each of the northern species, L. vejdovskyanus fi-om Waikare 

 and L. hicasi from Taupo. 



Phreodrilus lacustris, sp. n.* 



A very narrow worm in which the ventral chcetce are in couples 

 of two kinds : each couple consists of {a) a simple hook-like bristle 

 and {b) a hook with a very minute tooth in the back. These 

 chfetse measure 0-06 mm. in length. 



The ventral chsetse are absent on segments xii., xiii., though on 

 the latter segment they are replaced by special copulatory chsetse. 



Dorsal chastse solitary, capilliform, beginning on segment iii. 



The clitellum covers the hinder part of segment xii. and the 

 whole of xiii. 



The male pores are in line with the ventral chaetae at the hinder 

 margin of segment xii. 



The oviducal pores are in the same line, at the boundary of seg- 

 ments xii. /xiii. 



The spermathecal pores are in line with the ventral chsetae at 

 the anterior margin of segment xiii. 



Copulatory chcetce, a pair of couples ; each pair in a special ovoid 

 glandular follicle just behind the spermathecal pore. 



The preclitellar nephridium appears to extend through segments 



vii. to X. 



No sperm-sacs ; but loose developing spermatozoa in segments 



viii. to xii. 



Spermiducal gland of large size, filling segment xii., slightly 

 convoluted, receiving the sperm-duct at its short, nari-ow neck, 

 where it enters a large protrusible penis, enclosed in a muscular 



* A detailed account of this species has been sent to the Editor of the Quart. 

 Journ. Micros. Sci. 



