234 ME. F. E. BEDDAKD ON NEW EAETHWORMS. [Mar. l9, 



species of Microscolex and Acanthodrilus agree in that the sperm- 

 sacs are in xi. or in ix. and xi. j this is not a usual position. With 

 this may be compared the fact that the Australian Cryptodrilids 

 frequently agree with the Australian Perichsetas in that the sperm- 

 sacs are in segments ix., xii., also not a usual position. 



(5) Microscolex gracilis, n. sp. 



This species might easily be confounded with Microscolex 

 diversicolor, at least with the less strikingly-coloured examples of 

 that species. It has precisely the same dark purple colour dorsally, 

 the implantation of the setae being yellowish white ; the end of the 

 body, too, has the quadrangular aspect of the corresponding part of 

 the body in Microscole.r diversicolor. It is, however, in spite of 

 this superficial likeness, quite a different species. 



There were three examples, of which the largest measured 

 72 mm. ; the diameter was 2 mm., except at the clitellum, where 

 it was 3 mm. This individual consisted of 88 segments. It 

 is therefore a long and slender worm ; the clitellum is very 

 prominent. 



It may be at once differentiated from Microscolex diversicolor by 

 the fact that the prostomium is not continued by furrows over the 

 whole of the buccal segment. 



The setse are more or less distant, being divided by equal 

 distances at the posterior end of the body, where the middle line of 

 the segments is ridged. The sette are here particularly large. 



The clitellum occupies segments xiii.-xvi. and is complete. 



I could not see any dorsal pores. 



The male pores are separated by moderately wide intervals from 

 each other ; the orifice is wide and surrounded by a crenate 

 margin. 



The first septum separates segments iv./v. Septa is./xii. are 

 thickened. 



The gizzard is well developed ; it lies in segment viii. 



The nephridia begin in segment ii. ; they end in a muscular sac. 



The sperm-sacs are in xi., xii. In a specimen investigated by 

 longitudinal sections they occupied segment xi, only. The testes 

 and sperm-duct funnels lie in x. 



The spermiducal glands are stout and massive ; they have a 

 shghtly sinuous course and occupy thi-ee segments. The penial 

 setae are also stout and not particularly long. They are bent like 

 a bow, slightly expanded at the free end, but not ornamented. 



The muscular duct, when traced back into the glandular part of 

 the spermiducal gland, is seen to stop abruptly ; its lining epithe- 

 lium suddenly ending and being replaced by the indistinct lining 

 epithelium of the glandular part of the organ, rollowed in the 

 other direction, the duct winds about and receives the sperm-duct 

 a considerable distance in fi-ont of its external orifice ; the latter 

 opens at the end of a papilla, which projects into the interior of the 

 gland-duct, which is at this point widened : it is suggestive of the 

 penis of the Tubificidae, &c. Further down the duct receives the 



