210 On South- A mer lean Tubiticidaj. 



lie the spermatozoa ; I couM iiiid no trace of spermatophores. 

 The duct of the spermatheca leading from this sac is long 

 and narrow ; rather more tiian lialfway down there is a slight 

 swelling and a kind of trap formed by a sudden change in 

 the height of the lining epithelium ; the structure is very 

 suggestive of the spermatheca of Marionia sphrtgnetorum 

 recently described by Micliaelsen *. 



4. Hesperodrilus pellucidus, sp. n. 



This species is very like the last, differing, however, in a 

 few small points. Its colour when preserved is brownish, 

 instead of an opaque white. The dorsal capilliform setaj are 

 not so long and the spermiducal gland is a little different in 

 form. In other respects it agrees entirely with Ilespero- 

 drilus albus. 



1 conclude with a definition of the genus and the species : — 



HESPERODRILUS, gen. nov. 



Dorsal setai ca|)illiformonly ; ventral setai two toeach bundle, 

 one uncinate, the other simple. Male pores on segment xii., 

 spermathecal pores on xiii. Spermiducal gland opening into 

 protrusible penis, together with sperm-duct ; no distinct 

 "prostate." Spermathecai long. No spermatophores (?). 



(1) Hesperodrilus branchiatus, sp. n. 



Dorsal setse short anil slender. Posterior thirteen segments 

 with j)aired branchial processes. 



(2) Hesperodrilus niger, sp. n. 



Body strongly pigmented dorsally. Dorsal seti\3 short 

 and slender. 



(3) Hesperodrilus albus, s[). n. 



Dorsal setse do not commence until segment iii. Spermi- 

 ducal gland communicates with penis by a narrow tube. 



(-1) Hesperodrilus pellucidus, sp. n. 



Dorsal sctic do not commence until segment iii., slender. 

 Spermiducal gland only separated by a short constriction 

 from penis. 



* Arcli. f. luikr. Aiiat. xxxi. ]il. xx'ii. tii::. '2 r. 



