Species of JS'ortli. Ainer lean Oligochoeta. 289 



■a few scattering cells at the external opening. The 

 length of the funnel of the sperm duct is about twice its 

 diameter, and the duct itseh is very slender, much coiled, 

 ^nd confined to XII. 



F. agilis is distinguished from the other species of the 

 genus, except F. hisetosa and the two species recently 

 described by Nusbaum (10), by the number of setae 

 in each bundle, and it is distinguished from these by 

 the form of the brain and by other characters. The 

 spermathecse are more nearly like those of F. oligosetosa, 

 but the dissimilarity in the number of somites and of 

 septal glands, together with the differences in the neph- 

 ridia, in the duct of the spermathecae, and in the brain, 

 clearly distinguish the two species.* 



EnchytrcBUS {Halodrilus) Uttoralis Verrill. 



Verrill's description of this species (20, p. 623) contains 

 no account of the reproductive organs, and consequently 

 its relation to other Oligochseta has been quite uncertain. 

 Vejdovsky (18, p. 45) placed it with the Tubificidae, 

 while Vaillant (16, p. 292), Michaelsen (7, p. 50), and 

 Beddard (1, p. 312) have considered it as an enchy- 

 traeid. As a number of specimens, many of which were 

 sexually mature, were obtained by me at Wood's Holl, 

 Mass., in August of the present year (1895), I am able 

 to extend the description somewhat. I think there is no 

 doubt that these specimens belong to Yerrill's species, 

 since they correspond very closely to his description and 

 were extremely abundant in precisely the same sort of 

 situation in which he found his, namely, in dead sea- 

 weed and under stones near high-water mark, those under 



* Since 1he above description was written, an account of four new species of 

 Friderieia from the vicinity of Philailelphia has been received from Mr. J. Percy- 

 Moore (Proc. Acad. Nat. Sci. Phil.. 18:ir), p. 311). Of these F. longa is auite similar 

 to F. aoiliif in several characters. The arrangement of the setee is somewhat 

 different in the two species, and the number of diverticula of the spermathecaa 

 is somewhat greater in F. agilis than in F. longa, but the most obvious differ- 

 ence is in the characti'r of the salivary elands. Other differences may appear 

 when more is known of the nephridia, the dorsal vessel, and the reproductive 

 organs of the latter species. 



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