DESCRIPTIONS OF GENERA AND SPECIES 487 



(7) Digaster sylvaticus (FLETCHER). 

 Didymogaster sylvaticus, FLETCHER, loc. cit., p. 554. 



Definition. Length, 80 mm.; diameter, 12 mm.; number of segments, 120. Prostomium 

 incomplete. Clitellum, XIII-XVIII. Setae of outer row sinuous. Dorsal pores commence 

 V/VI. Oviducal pores close to median line. Gizzards in FT, VII ; intestine arranged 

 in a corkscrew fashion. Last hearts in XIII ; supralntestinal trunk double. Sperm-sacs 

 in IX, XII; spermathecae in VIII, IX, with small pyr if orm caecum. Hob. Burrawang, 

 Springwood, Jervis Bay, N. 8. W. 



FLETCHER mentions in this species in each of the four segments v-ix a pair of 

 peculiar bodies on either side of oesophagus richly supplied with blood-vessels, but 

 is unable to suggest their nature. There is evidently an inaccuracy with regard to 

 the spermathecae somewhere, either in the description or figure ; he describes them 

 as lying in segments vii, ix, but seems to figure three pairs in vii, viii, ix. 



Genus MEGASCOLIDES, McCoy. 



Syn. Cryptodrilus, FLETCHER, et alii (in part.). 

 Plutellus, BENHAM (? non PERRIER). 



DEFINITION. Wephridia paired. Spermiducal glands in XVIII, tubular in form. 



As has already been pointed out there are no differences of importance which 

 serve to distinguish Plutellus from Megascolides. The wide separation in range is 

 the only reason indeed which could possibly, in my opinion, lead to their generic 

 separation; and this, be it observed, is curiously paralleled by the Marsupials. This 

 being the case, the name Megascolides ought to be dropped in favour of Plutellus ; 

 but I do not consider it to be yet proved that BENHAM'S P. perrieri is congeneric 

 with PERRIER'S P. heteroporus. The latter species has been stated to possess ovaries 

 which are situated in front of the testes. This is, of course, if true, a unique case ; 

 so too is its other distinguishing feature, viz. the fact that the nephridia are confined 

 to one segment, the funnel not lying, as is elsewhere invariably the arrangement, 

 in front of the septum. No doubt many naturalists have thrown doubts upon 

 PERRIER'S statements concerning these two important points, and it must be admitted 

 that they seem from our present knowledge to be improbable ; nevertheless, no great 

 harm will be done if we leave the matter for further proof, and regard the genus 

 Plutellus as ' iticertae sedis.' BENHAM'S species will be treated as a Megascolides. 



The species are here grouped according to the number of spermathecae and sperm- 

 sacs. It is noteworthy that only one of the species which has only a single pair 



