14G Illinois State Lahoratoinf of Natural History. 



being readily seen through the body wall of living 

 specimens of the Illinois species. The dorsal one is con- 

 siderably larger than the other. (4) A perienteric sinus 

 occurs in each species. 



From the similarity of the characters just mentioned 

 and of others referred to in the appended table, it is 

 evident that the two forms are very closely allied. Were 

 it not for the presence of the prostate glands in the one 

 here described there could be no question about their 

 belonging to the same genus, and, as it is, I do not feel 

 justified in creating a new one, but prefer, for the present 

 at least, to associate the new species with Benham's by 

 naming it Sparganophilus eiseni. 



The chief characters by which it may be distinguished 

 from S. tamesis are, as already mentioned, its greater 

 size, the dorsal position of the outer setaB and sperma- 

 thecal pores, the latero-ventral ridges of the clitellar 

 region during the reproductive period, and the presence of 

 prostate glands in some or all of somites XX [II-XXVI. 



Necessary figures and additional details will appear in 

 the more complete report to be published later. 



Sparganophilus tamesis. Sparganophilus eiseni, 



Clitellum 



Prostomium 



Kale pore 



Bperra-sacs 



Spermathecaa 



Gizzard and oesophag- 

 eal diverticula. 



Typhlosole 



Tascular bystem 



Somites XVI— XXIV. with 

 part of XY and XXV. 



Not marked off from the 

 peristomium by a groove 



Inconspicuous. Between 

 XVllI and XIX. without 

 accessory organs. 



Two pairs; In XI and XII, 



Simple. Three pairs. 



Absent. 



Absent. 



Perienteric blood sinu? 

 Two longtegumentary vef^ 

 eels on each side traverse 

 the anterior somites with- 

 out communicating wiih 

 the alimentary tract. No 

 Buhneural vessel; the only 

 commissural vessels situ- 

 ated anteriorly. 



XVI-XXV with part of XV. 

 Diminishing on XXIV and- 

 XXV. 



Not marked off from the 

 peristomium. 



Inconspicuous. Upon an- 

 terior part of XIX, 



Two pairs; in XI and XIL 

 Simple, Three pairs. 



Absent. 



Absent, 



Perienteric blood sinus. 

 Two long tegumentfiry 

 vessels on each side trav- 

 erse the anterior somites 

 without communicating 

 with the alimentary tracU 

 No subneural vessel; the 

 only commissural veusels 

 situated anteriorly. 



