THE OLIGOCH.ETA OF NATAL AND ZULULAND. 453 



2 a. Coustantly two setos in a l>undle. Spennathecte without 



diverticula. . Fridericia pevegrinabunda n. sp. 



2 h. More than two setae in a bundle, 4-6 ; the middle ones 



being smaller than the outer ones. Spermathecaj with 

 two diverticula. . . Fridericia perrieri (Vejcl.) 



3«. Clitellum includes the fourteenth to the sixteenth seg- 

 ments. Gizzard, if present, is placed before the region 

 of the sperm-sacs. .... 4 



3 h. Clitellum Ijegins behind the twenty-fifth segment. A mus- 



. cular gizzard in the seventeenth and eighteenth seg- 

 ments. (Fam. Lumbricidse). . .24 

 4«. One or two pairs of prostates open at the male pores, or 

 near them, at the seventeenth or eighteenth segment, 

 or at the seventeenth and nineteenth segments. (Fam. 

 Megascolecidge. with the exception of some scarce 

 species). ..... 6 



4 b. Prostates absent. (Fam. Glossoscolecida; and some 



scarce species of Megascolecidse such as Ocnero- 



drilus africanus). . . . .14 



5 o. One pair of prostates open at the eighteenth segment. (Sul)- 



fam. Megascolecinse). .... 6 



5 b. One pair of prostates open at the seventeenth segment, or 



two pairs open at the seventeentli aiid nineteenth seg- 

 ments. ...... 7 



6 u. At each setal segment there are eight widely paired setai. 



Two pairs of spermatheca3 open in the furrows between 

 segments 7-8 and 8-9. No gizzard. 



Pontodrilus bermudensis bedel, f. typicus 



6 h. At each setal segment there are many more than eight 



setaj ; they form nearly complete circles rotuid the 

 body. Four pairs of spermatheca^ open at the inter- 

 segmental furrows of segments 5-9. A large gizzard. 

 Prostate with racemose glandular portion. 



Pheretima heterochasta (Mich.) 

 7 «. In each post-clitellar segment six to twelve small sac- 

 like micronephridia occur. Seta3 all ventral in position. 

 Two muscular gizzards present. (Sub-fam. Trigas- 

 trina;, gen. Dichogaster). ... 8 



7 h. In each post-clitellar segment there is one pair of large 



meganephridia. ..... 9 



8(f. One pair of prostate pores at the seventeenth segment. 



Dichogaster crawi Eisen ^.--'-'T't^'-'- 



•LI 



BR AR Yj; 



