Mr. W. F. Kirby on the Family Hetrodidse. 141 



stomium is incorrect in representing it as much too narrow ; 

 it is more like that of the preceding species, but cuts through 

 the first segment. The chaetse are not in a continuous circle, 

 but are quite evidently arranged in couples as in Plagiochosta. 

 The specimen must have been more deeply pigmented than 

 P. sylvestris, for whilst that is now absolutely colourless, this 

 is faint brown. 



The following points seem to differentiate it from P. punc- 

 tata : — (1) The dorsal gap is three times and the ventral gap 

 twice the length of a normal gap. (2) The spermiducal 

 glands open on distinct papillae, and there is no such marked 

 ridge round the ventral " area " in this region as occurs in 

 P. punctata (this may possibly be due to imperfect preserva- 

 tion). (3) The spermatheca has two peculiar diverticula in 

 place of a single cylindrical one ; of these, one is an oval 

 pouch, the other is a three-lobed pouch with a narrow neck; 

 they both open close together into the duct of the main sac. 

 (4) The chseta3 measure 0*22 millim., and are stouter and 

 more strongly curved internally than in P. sylvestris. 



Both these species agree with P. punctata in having 13 

 couples of chretas on each side, which are inserted between 

 distinct and separated bundles of longitudinal muscles, of 

 which there are 12 on each side ; these are visible in trans- 

 verse sections even between the chsetal rings. The most 

 dorsal and most ventral couples of chsetas are separated from 

 their fellows respectively by a broader bundle, which appears 

 to vary in size in the three species. 



The nephridiopores alternate in position from segment to 

 segment more or less regularly, and, as in P. punctata, the 

 ventral pore lies between the third and fourth bundle, the 

 dorsal pore between the ninth and tenth bundle, counting 

 from below, as I have figured in pi. xv. fig. 17 (loc. cit.}. 



Dunedin, 

 Aug. 11, 1898. 



XVII I. — Notes on the Family Hetrodidae, with a List of the 

 described Species. By W. F. Kirby, F.L S., F.E.S., &c. 



[Concluded from p. 102.] 

 Notes on various Genera and Species of the Family Hetrodidae. 



Genus Hetrodes, Fisch. 



Walker has described four species, allied to H. pupus, Linn., 

 viz. II. marginatus, productus, macrurus, and abbreviatus. 



