BY E. J. GODDARD. 789 



arduous demands. The conditions of habitat, the small number 

 of forms constituting the family, together with the geographical 

 distribution of the various genera and species, would seem to 

 indicate that the Phreodrilidce are the remnants of an old 

 Antarctic stock, the representatives of which are now to be found 

 under conditions comparable with those of the stalked crinoids of 

 the deep sea. The family is generally regarded, phylogenetically, 

 as an offshoot of the Tubificid stem; and, in many ways, as being 

 intermediate between the Tubificidce and Lumbriculidce. " In 

 Phreodrilus," according to Beddard, in his description of Phreo- 

 drilus subterraneus, " we get the first stage in the development 

 of capilliform seta?, and the commencing reduction of one pair of 

 spermiducts." In P. subterraneus, the sigmoid, unnotched, 

 ventral setae are quite different from those of Tubificids, and the 

 same applies in the case of Phreodriloides, and Plireodriliis 

 Kerguelenensis and P. beddardi. But in all other species of 

 Phreodrilus, and in Astacopsidrilus species, the bifid type of 

 the Tubificid seta is foreshadowed. The Lumbriculidce have all 

 seta? of the Lumbricid type, and these are, in some forms, of the 

 bifid pattern definitely established in the Tubificidce. 



The posteriorly situated spermathecse indicate also a connection 

 between the Lumbriculidce and the Phreodrilidce. 



Again, the position of the genital aperture in Phreodrilidce, 

 and the apparent glandular nature of the spermiducal funnel 

 epithelium in Astacopsidrilus, may possibly signify a reversion 

 towards earlier characters of some lower members of the group, 

 e.g., Enchytrceidce. However, much assistance in this question 

 might be very probably obtained by a study of the development 

 of the forms. 



In connection with the question of distribution, it is interesting 

 to note that the Lumbriculidce are, I believe, restricted to the 

 Northern Hemisphere, and the Phreodrilidce to the southern 

 portion of the Southern Hemisphere. 



In regard to the spermathecal structures, the new genus, 

 Astacopsidrilus, is of special interest, inasmuch as it is inter- 

 mediate between Phreodrilus and Phreodriloides in that connec- 



