ANNELID GENUS CAMBARINCOLA — HOFFMAN 



349 



Figure 57. — Distribution of the three species of the Philadelphica subgroup. O) C. phila- 

 delphica; G, "amplistomate" variety of philadelphica; (J, C. macrodonta; 9, C. chiro- 

 cephala. 



bursa, subequal in length to the prostate gland. Spermiducal gland 

 relatively small, subequal to or shorter than length of bursa, its 

 ental end recurved caudomesad prior to entry of the anterior deferent 

 duct. Prostate relatively large, nearly as long and thick as sperm- 

 iducal gland, the terminal bulb large and conspicuous. 



Spermatheca long and slender, the ectal half curving latcrad 

 around the gut, ental half more or less abruptly enlarged to 1.5 to 2 

 times the diameter of ectal portion, the apex bluntly acuminate, not 

 set off as an evident ental process. Total length of spermatheca 

 somewhat greater than diameter of segment vii. 



Variation. — Individual variation in this species is very slight, 

 involving chiefly differences in size of the body. The proportions 

 of the reproductive tracts remain constant for a given locality. 



There is, however, some evidence that the sexual organs arc subject 

 to the influence of geographic factors affecting variation. There 

 appears to be an east to west decrease in the spermiducal gland 

 length as indicated by the illustrations (JBgs. 47, 49). In Indiana 



