556 



Diplocardia conunnnis Carman. — [Garnian, '88:47.] The first 

 species of the genus to be described. It differs from its congeners in 

 having a double dorsal vessel extending throughout the greater part 

 of the length of the body. Abundant in the prairie soil of central 

 Illinois. Nothing is known of the limits to its range. 



Diplocardia singularis (Ude). — [Ude, '95 : 129.] Common in the 

 soil of tlie upland regions of east-central Illinois. 



Diplocardia singularis fluznatilis n. var, (PI. XLI,Fig. 4). — Abun- 

 dant in the soil of the bottom-land forests at the junction of the Illi- 

 nois and Spoon rivers. 



Diplocardia verrucosa Ude (PI. XIJ. Fig. 13). — [Ude, '95: 

 133.] Described from specimens collected at Omaha, Nebraska. Abun- 

 dant in the soil of the bottom-land forests of the Illinois and Kas- 

 kaskia rivers. 



Sparganophilus eiscni Smith (PI. XIJ, Fig. 6-9). — [Smith, '95a: 

 142.] An aquatic species which is abundant in the mud of the bottom 

 and margins of many rivers and lakes east of the Mississippi River. 



Helodriliis tetraedrus (Savigny) and H. t. hercynitis (Michael- 

 sen). — [Michaelsen, '00:471-473.] Amphibious, and widely dis- 

 tributed throughout the United States and in many other parts of the 

 world. 



Hclodrilus foctidns (Savigny). — [Michaelsen, '00:475.] A con- 

 spicuously transversely banded species of nearly world-wide distri- 

 bution where Europeans have settled, and especially abundant in com- 

 post heaps and barnyards. 



Hclodrilus roseus (Savigny). — [Michaelsen, '00: 478.] An abun- 

 dant, widely distributed species which lives in soil. It usually has 

 conspicuous papilLx associated with some of the setx bundles of IX 

 and X. 



Helodrilus caliginosus trapcijoidcs (Dugcs), PI. XLI, Fig. 14 

 and 15. — [Michaelsen, '00:483.] The most abundant species in the 

 long-settled parts of the United States, and found almost universally 

 where Europeans have settled. It is easily recognized by the con- 

 spicuous glandular pads associated with the ventral setae of IX-XI, 

 XXVIII, XXX, and XXXII-XXXIV. 



Hclodrilus subrubicundus (Eisen). — [Michaelsen, '00 : 490.] 

 This species is widely distri])utc(l in the Northern Hemisphere, and 

 in other parts of the world where Europeans have settled. In Illinois, 

 specimens have most frequently been found in situations subject to 

 sewage contamination. 



Hclodrilus tenuis (Eisen). — This species was named in 1874 by 

 Eisen, who described only the external characters. These arc insuffi- 

 cient to fix the identity of the species. An examination of specimens 



