462 FRANK &. BEDDARD. 
are each furnished with two diverticula; one is a moderately 
long tube of equal diameter throughout, and bent upon itself 
like a “Pan’s pipes ;” the other is a pear-shaped body attached 
by a long stalk to the duct of the spermatheca. I have found 
that in this species there are sometimes a pair of these struc- 
tures (fig. 6), of which one may lie in the cavity of the segment, 
anterior to that in which the spermatheca lies ; this increases 
the resemblance of the structures in question to diverticula. 
These bodies are of a perfectly different structure from diver- 
ticula; each consists of a mass of granular cells which are 
prolonged and form collectively the stalk of the organ,—it 
is in fact merely a bundie of unicellular glands, which pour their 
secretion into the duct of the spermatheca. 
In P. aspergillum, Perrier has directed attention to a 
number of small white glands which open on to the exterior, 
round the orifices of the spermathece and vasa deferentia. 
These glands (figs. 3, 4, 5) are identical with those just referred 
to in P. Houlleti. 
In Pericheta mirabilis, the same glands are found and 
their orifices are exceedingly conspicuous. I observed four 
apertures. There are three apertures in one segment—two 
lateral and one median, and a single median aperture in the 
following segment. I neglected to note the exact position of 
the segment occupied by these pores, but the anterior, at least, 
also contains a pair of spermathece. The apertures of the 
glands are, as remarked, extremely conspicuous, and might 
easily be taken for spermathecal openings ; in fact, the useless- 
ness of external characters only, as a guide to zoological 
affinities, is strikingly exemplified by this case. With each 
pore communicates several bundles of unicellular glands, which 
converge at the point of opening, or sometimes earlier. 
So far as I am aware, these peculiar glands are confined to 
the genus Pericheta.' 
1 Perrier has described in P. affinis what are apparently similar glands ; 
in that species they are connected with the genital papille which occupy 
segments 17 and 19; it is possible that the papille in Pericheta are 
often connected with such glands, 
