50 



Liniiliriciiliis inconatdus (Smith). 



In life reddish, anteriorly greenish. Prostomium rounded, 

 length U times the basal width. Spermiducal pores on X (excep- 

 tionally on XI). Two pairs of oviducal pores, XI/XII and 

 Xll/Xill. Spermatheeal pore.s on XI— XV or XII— XVI. Brain 

 anteriorly, but slightly, concave, posteriorly with a deep, round- 

 ed trilateral incision. Contractile CKcal ti-ansverse appendages 

 of the dorsal vessel beginning in XI, becoming larger and more 

 branched in succeeding somites. Two pairs of testes and two 

 pairs of spermiducal funnels in IX and X. Atria pyriforra, 

 one pair in X (exceptionally in XI). Two pairs of ovaries and 

 two pairs of oviducal funnels in XI and XII. Five pairs of 

 spermathectein XI — XV or XII — XVI. Nocopulatory (albumen) 

 gland. Length, 30 — 60 mm. Diameter, .6 — .8 mm. Number of 

 somites, 150 — 200, or more. 



If the above disposition of the two species under discussion 

 be correct, and if the views of Michaelsen (1902) concerning 

 the phylogeiietic relationships of the lumbriculid genera are 

 well founded, the species liic())i.sfai/,s seems to have the more 

 primitive condition -of spermiducal structures, and L. varicgatus 

 mayhave been derived from it by thedisappearance of the ante- 

 rior pair of testes and of sperm-ducts and a reduction in the nu m- 

 ber of anterior somites. The specimen of L./iinnisfatisreierred 

 to above, in which the spermiducal pores are on a somite pos- 

 terior to the somites containing the testes, presents a condi- 

 tion normal to families higher than the Liimbrirulidd' but not 

 ordinarily found in that family. 



The transfer of the American species from the genus 

 Trichodrihts to Lionbriciiliis leaves the former genus much 

 more homogeneous and simplifies its definition. 



University of Illinois, Decembei' 16, 1905. 



