546 



versity of Michigan Biological Station, located on the shore of Douglas 

 Lake. These worms were found living in the wood and under the 

 hark oi decaying logs, and sometimes immediately l)eneath such logs. 



EXTERNAL CHARACTERS 



The purplish hrown coloration is most pronounced on the an- 

 terior dorsal surface, and the under parts are distinctly paler. The 

 clitellum is hrownish huff. The length of the type specimen is 135 

 mm. and its maximum diameter is 6 mm., while the corresponding 

 dimensions of the paratypes are 97-140 mm. and 5-6.5 mm. respec- 

 tively. The Michigan specimens average somewhat smaller than those 

 from Illinois. The diameter of the peristomium of the type specimen 

 is about 3 mm., and then follows a gradual increase in diameter to 

 XII, where it is 5 mm., and from there it remains uniform until the 

 clitellum is reached, where the maximum of 6 mm. is attained. Pos- 

 terior to the clitellum the diameter is nearly uniform and about 4 mm. 

 This region is slightly flattened in the living worm and there are dis- 

 tinct dorso-lateral and ventro-lateral angles. There are 100 somites 

 in the type specimen, which shows evidence of having lost a number 

 of somites from the posterior end. In the paratypes the number is 

 134-142. The somites anterior to the clitellum are slighlly longer 

 and more distinct than the posterior ones. 



The arrangement of the setae in somites anterior to the clitellum 

 is indicated by the formula aa: ah: be: cd: dd = 6: 1:5: i : 20; dd 

 equals one half of the circumference. Posterior to the clitellum, be 

 becomes relatively somewhat greater and dd somewhat less. The 

 clitellum is on XXVII-XXXVII. In the type specimen it is not as 

 well developed on XXVII as on the other somites. In one paratype 

 it is on Yz XXVII-XXXVIII. The clitellum is saddle-shaped and 

 reaches its most ventral limit on XXXIV, where' the margins are only 

 ^•33-1-5 rn"^- apart. On XXVII and XXVIII the ventral margin is 

 slightly dorsad of b; on XXIX, between a and b; and on XXX- 

 XXXVI, includes the ventral seta;. Tubercula pubertatis are lacking. 

 The paired spermiducal pores are on XV, slightly dorsad of b. Each 

 is in a deep transverse groove and is bordered by a slightly elevated 

 glandular area which extends ventrally to b, anteriorly as far as XIV/ 

 XV, and posteriorly encroaches on XV^I. The oviducal pores are 

 small apertures slightly dorsad of b on XIV. The nephridiopores are 

 large and easily seen, and their position is similar to those of other 

 Luinbricid(€. They are near the anterior borders of the somites, some 

 f)f them slightly farther dorsad than b, while others are approxi- 

 mately midway between the dor.sal setie and the mid-dorsal line. 



