ArticLte Il1].—A New North American Oligochaete of the Genus 
Haplotaxis.* By FRANK SMITH. - 
INTRODUCTION 
The only papers describing North American Haplotaxidae are two 
by Forbes (790 and ’90a) in which he describes Haplotaxis emissarius 
from Illinois under the name Phreoryctes emissarius. The present paper 
extends the original description by giving the positions of the gonads and 
spermathecae, hitherto unreported. It also includes the description of a 
new species, Haplotaxis forbesi, from the Illinois River. 
Forbes found no trace of reproductive organs in his specimens. 
The following quotation (’90a :108) indicates what he regarded as the 
important characters in which H. emissarius differed from H. menkeanus, 
the closely allied European congener: “It differs especially by the fact 
that the dorsal rows of setae are obsolete except on a variable number of 
the anterior segments and that the lateral vascular arches extend from 
the dorsal to the ventral vessel, instead of connecting only with the lat- 
ter.” Later, Michaelsen (’99) gave reasons for believing that faulty 
observations by earlier European investigators were responsible for these 
reported differences, and that the European species actually corresponded . 
with the description of Forbes in the absence of dorsal setae from most 
of the somites, and in the relation of the commissural blood-vessels. At 
this time Michaelsen considered that the various known forms of Haplo- 
taxis of the northern hemisphere all belonged to one variable species, H. 
gordioides (Hartmann). In a later paper (’05) he described another 
species, H. ascaridoides, from Lake Baikal, in Siberia, which differs 
chiefly in the number of spermathecae present in sexually mature speci- 
mens, there being four pairs in the latter species and but three pairs in 
H. gordioides. Since the immature specimens of the two species are 
extremely similar, and since only immature specimens of the North 
American H. emissarius were known, Michaelsen concluded (05 : 67) [ 
that the assumption that the latter species is identical with H. gordioides 
is not justifiable without a comparison of the reproductive organs. 
REPRODUCTIVE ORGANS IN HAPLOTAXIS EMISSARIUS (Forbes) 
Through the kindness of Professor Forbes I have had the privilege 
of examining the series of sections on which his description was partly 
based. I find vestiges of four pairs of gonads in 10-13. Two speci- 
mens in my own collection, from the same region (Champaign, Illinois) 
and from the same kinds of situations (tile drains) as were the type 
* Contributions from the Zoological Laboratory of the University of Illinois, 
No. 118. 
