1903. J OLIGOCHiETA FROM NEW ZEALAND. 223 



any details as to lymph-corpuscles, nephriclia, and certain other 

 anatomical features. 



Haplotaxis heterogyne, sp. n.* 



The p'ostommm, is long, but not annulated. 



The chcetce are four per segment, isolated, one dorsal and one 

 ventral on each side ; the form agrees with that found in H. gordi- 

 oides. The ventral chseta is from two to three times the length of 

 the dorsal, but less difference exists in the anterior segments. 

 The dorsal chsetae occur throughout the body. 



The clitellum surrounds segments xi. to g xiv. ; it is complete 

 and thickest laterally. 



The genital pores were not detected externally ; but the ducts, 

 traced in sections, meet the body- wall at points indicated below. 

 There are two pairs of male ducts which reach the epidermis in 

 segments xi., xii. anteriorly to the ventral chsetse. There is a 

 single pair of oviducal pores on segment xiii. laterad of the line 

 of ventral ch?et8e, but rather nearer the anterior margin of the 

 segment than these ; but they are much further back in their 

 segment than the male pores are. 



Two pairs of spermathecal pores lie at the anterior margins of 

 segments viii., ix. 



The alimentary canal is remarkable for possessing a strongly 

 muscular gizzard in segment iv. ; it is quite different from 

 a pharynx, which is here absent. A similar, but more extensive, 

 gizzard has been recorded by Michaelsen f for H. gordioides. 



The first pair of nephridia lie in segment x. ; they are rather 

 smaller than the postovarian nephridia. These organs are absent 

 in segments xi., xii., xiii., but reappear in segment xiv. et seqq. 



The nephridial canal perforates a string of large cells having 

 distinct boundaries and highly vacuolated cytoplasm. Each 

 nephridium reaches the epidermis close to the ventral chagta, 

 thi'ough a short " duct " formed of a highly granular syncytium. 



As in the ca,se of the sperm-ducts, I was unable to detect an 

 actual perforation or opening through the epidermis. 



Reproductive System (text-fig. 23, p. 224). — Two pairs of testes 

 and sperm-funnels occur in the usual positions in segments x., xi. 

 The sperm-duct leaves the large, thick, flattened sperm-funnel at 

 its ventral edge, as Beddard + found was the case in H. smithi. 

 But the sperm-duct in that species has the usual structure, 

 i. e. is surrounded by a definite epithelium. 



In the present species the sperm-duct perforates a series of cells 

 the boundaries of which are not distinguishable, and has an undu- 

 lating course in this syncytium, which extends up to the level of the 

 lateral line. The duct passes upwards to this level, then bends upon 

 itself, still within the syncytium, and reaches the body- wall in front 



* A detailed and illustrated account of this worm has been sent to the Editor of 

 the Quart. Journ. Micr. Sci. 



t Michaelsen, Zool. Jahrb. (S^'stem.) xii. p. 105. 



X Beddard, Ann. & Mag. Nat. Hist. ser. 6, i. p. 389 (1888). 



