AN ATTEMPT TO CLASSIFY EAETHWOEMS. 229 



In one species, Cr. purpureas, there are five median sper- 

 mathecse, instead of two pairs usual to the genus. 



2. Spermiducal pores on Somite xviii ; two pairs of tubular, 

 more or less convoluted prostates, in Somites xvii and xix, and 

 opening to the exterior on these somites. 



Family II. Acanthodrilid8e,Kosa ( = partly L.postclitelliens, 

 E. P. = partly Acanthodrilidse, Claus, Vejdovsky). 



Set 86, eight or twelve per somite, in couples or separate. 



Clitellum occupies xiii or xiv to xix, or fewer somites, or 

 extends to Somite xl ; either complete ventrally throughout 

 or only anteriorly. 



Spermiducal pores, one pair on Somite xviii, in line 

 with the inner setae. 



Prostate-pores on Somites xvii and xix, in same line as 

 spermiducal pores. 



Genus 8. Acanthodrilus, E. P., 1872 (= Mandane, 

 Kinberg, 1866). 



Setse eight, in couples or separate. 



Clitellum usually occupies Somites xiii to xix; some- 

 times one additional somite at each end, sometimes fewer; 

 usually complete in anterior somites, but leaving a non-glan- 

 dular ventral area on Somites xvii, xviii. 



Sperm -sacs. — Two pairs in Somites xi, xii. 



Prostates usually accompanied by sacs containing special 

 " penial " setse. 



[Prostomium more or less dovetailed into the peristomium. 

 Dorsal pores are present. 



Testes and ciliated rosettes in Somites x and xi. 



Spermathecse with appendices, and sometimes accompanied 

 by sacs containing " anterior penial ^' setee ; apertures in a line 

 with the inner couple of setae. 



Gizzard usually single, occupying two somites ; rarely two 

 separate gizzards in vi and viii. 



Pepto-nephridia are frequently present in the anterior 

 somites. Calciferous glands present. 



Dorsal vessel sometimes double. 



