468 FRANK E. BEDDARD. i 
In any case, therefore, it seems to be desirable to draw the 
attention of zoologists to this Earthworm, as it seems to con- 
nect the genus Pericheta with other forms. 
The most remarkable structural peculiarities of P. inter- 
media concern the excretory and reproductive organs. 
The genus Perionyx was distinguished by Perrier (38) from 
Pericheta, chiefly for the reason that each segment is fur- 
nished with a pair of nephridia. These organs in Pericheta 
usually consist of innumerable tufts of extremely fine tubules, 
which, as I have shown, form a network communicating with 
the exterior by many pores, and with the celom by numerous 
ciliated funnels, in each segment. Although Perrier did not 
observe the microscopical characteristics of the nephridia of 
Pericheta, he did point out such obvious differences between 
the nephridia of this genus and of other Earthworms as could 
be discerned on a dissection of the worm; and these differences 
led him to separate Perionyx, which agrees with Lum- 
bricus and many other genera in having a single pair of dis- 
tinct nephridia in each segment of the body. Pericheta in- 
termedia and, according to Fletcher’s description, P. Bakeri, 
agree with Perionyx, and differ from other Pericheta in their 
nephridia. 
The second point of interest in the structure of the two last- 
named species of Pericheta is in the form of the “ prostate,” 
or atrium, as it is better termed. In nearly all the species of 
this genus the atria form branched glandular structures, being 
frequently divided by furrows into variously sized lobes. The 
branched character of the atrium is but little marked in P. 
Newcombei (see Beddard, 4) as compared with many. other 
species. In P. intermedia the atria are precisely like those 
of Acanthodrilus and Typheus; they are long tubular 
organs much coiled upon themselves; their cavity is simple, 
not branched, and the histological structure of their walls is 
quite indistinguishable from Acanthodrilus (see Beddard, 
3). Limagine, from Mr. Fletcher’s description of P. Bakeri, 
that the atria of this species of Pericheta are like those 
of P.intermedia. A very interesting Pericheta has been 
