NEW GENERA AND SPECIES OF EARTHWORMS. 257 



like processes to long tubular caeca, many times as long as the 

 diameter of the sac from which they arise. There appears to be 

 no regularity in the arrangement of these caeca; they are not 

 symmetrially disposed, nor are the longer outgrowths arranged 

 in a definite fashion with reference to the shorter caeca. The 

 walls of the sperm-sacs (fig. 6) appear to be almost entirely 

 cellular; the muscular coat^ though present^ is extremely thin. 

 They contained no developing spermatozoa^ which may perhaps 

 account for their fineness. There are three pairs of spermato- 

 thecae, apparently lying in Segments 7, 8^ and 9. Like the sper- 

 matothecae of other Geoscolicidse, they have no diverticula; they 

 are exceedingly slender pouches of great length (see fig. 5), 

 longer than those of any allied form : the muscular fibres in 

 the walls of the spermatothecae cross each other diagonally — 

 forming, in fact, a double spiral. 



The Geoscolicidae of Rosa fall into two groups, which are 

 also marked by their geographical distribution. The relation 

 between the classification of the family and the distribution 

 has not yet been pointed out ; I may therefore call attention 

 to the following facts. 



I previously divided the group into three families — Uro- 

 chaetidse, Geoscolicidae, and Rhinodrilidae, but I am now of 

 opinion that my division is not the most satisfactory ; nor do I 

 think that Benham's two families are more satisfactory : these 

 families are Geoscolicidae and Rhinodrilidae. 



I am disposed to think that the scheme here advanced is 

 more in accord with what we know of the structure of these 

 worms ; I would divide them into two families — Geoscolicidae 

 and Microchaetidse. . 



The first family — Geoscolicidae — includes my two families 

 Urochaetidaeand Geoscolicidae — Hormogaster and Glyphi- 

 drilus, and +Urobenus, Rhinodrilus, and Anteus; it 

 equals Benham's Geoscolicidae + Rhinodrilus and Uro- 

 benus. 



It includes, therefore, the following genera : 



