108 Illinois State Laboratory of Natural History. 



of the elm, taken from a tile in a farm drain. Here, in com- 

 pany with a large number of the ordinary blind crustaceans of 

 the subterranean waters of this region {Asellus stygius and 

 Crangonyx mucrotiatus), I found three living examples of the 

 same worm as that received from the well ten years before, and 

 these proved upon examination to belong unquestionably to 

 the genus Phreoryctes, but to a species undescribed. 



From the other Oligochseta the family Phreoryctidae and 

 its sole genus, Phreoryctes, are distinguished by the long and 

 slender form, the great number of segments, the thick cuticle 

 and weak longitudinal muscular layer ; by the simple setie, 

 placed singly in four longitudinal rows, two ventral and two 

 dorsal (the latter sometimes aborted) ; and by the convoluted 

 nephridia imbedded in fat cells and opening to the surface be- 

 fore or behind the setie. The ventral ganglia present two 

 swellings or enlargements in each somite. The sexual glands 

 are said to occur in segments nine to twelve, and the rcceptacula 

 seminis in segments six to eight. 



Phreoryctes emissarius, Forbes.* 



This worm is allied to P. menkeanus by its great length, 

 its pale red color and iridescent luster, and its subterranean 

 habit, by the presence of ventral organs beneath the nerve 

 cord, and by the three pairs of nerves from each ventral gan- 

 glion. It differs especially by the fact that the dorsal rows of 

 setai are obsolete except on a variable number of the anterior 

 segmentsf and that the lateral vascular arches extend from the 

 dorsal to the ventral vessel, instead of connecting only with the 

 latter. The worm is at least seven or eight inches iu length 

 by about .6 to .7 mm. in thickness, and my longest specimen 

 (an imperfect one) contains three hundred and seventy-five 

 segments. 



The head or prostomium is not transversely lobed, either 

 without or within, and thin vertical transverse sections give 

 no hint of a cephalic pore. The seta) (Pl.A'I., Figs. 1 & 2) be- 

 gin with very small dorsal and ventral pairs in the first post-oral 



* Amer. Nat. May, 1890, v. xxiv., p. 477. 



f None of my specimens are entire, and T am not able to give the 

 characters of the posterior segments. 



