ON THE ANGUILLULIDÆ. | C: 
cylindrical intestine; anus none(?) or exceedingly indistinct. Caudal extremity 
obtuse. Generative aperture of the female near the middle of the body.” 
P. sırınum, Leidy. 
“ Body cylindroid, most narrowed anteriorly. Head without appendages. Caudal ex- 
tremity broad, obtusely conical. Length 5 lines; breadth lth of a line.” 
« An active, wriggling, glistening-white worm, found among beds of Vallisneria ameri- 
cana growing in the river Schuylkill, near Philadelphia." 
36. NEMA, Leidy. 
Proceed. of Acad. of Philad. viii. (1856) 49. 
Gex. Cmar. “ Body ascaridiform. Head without appendages. Mouth unarmed, large, 
infundibuliform ; esophagus tubular, membranous, expanding into a simple, straight 
intestine; anus ventral. Tail conical, acute, recurved. Generative aperture near 
the middle of the body.” 
N. VACILLANS, Leidy. 
“Body white, glistening. Length 13™™; breadth ‘050mm, Tail ‘115mm long,” 
“ An active, wriggling worm, found about some dead specimens of a black Phryganea, 
whith was infested with a fungous parasite, and attached to stones at the water's edge of 
a small brook near Philadelphia.” 
37. UROLABES, Carter, 
“The generie name of Urolabes, which I have employed, should only be viewed as 
provisional. It has been chosen from the striking habit which all these worms have of 
attaching themselves to some object by the tail, whether it be by embraeing it or by 
adhering to its surface. Hence the tail would appear to be both prehensile and adhesives 
if not suctorial. Having once fixed themselves in this way, they keep up an undulating 
movement from the tail forwards, which, in the absence of any evident purpose, seems 
more for respiration than anything else."— Ann. of Nat. Hist. ser. iii. vol. iv. p. 99. 
Amongst the ten species described by Carter, there are representatives of several 
genera; and I have been able to assign positions to three of the species—one in the 
genus Dorylaimus, one in Chromadora, and one in Symplocostoma. Of the remainder, 
three (V. gleocapsarum, U. labiata, and U. tentaculata) seem, by the form of their 
esophagus, almost to belong to the genus Rhabditis, although this is somewhat nega- 
tived by the absence of caudal ale in the male of U. gleocapsarum, the males of the 
other two species not having been discovered. 
aU, GLŒOCAPSARUM, Carter. 
Loc. cit. p. 40, pl. iii, fig. 25. 
“ Female, linear, cylindrical, striated transversely, gradually diminishing towards the 
head, which is obtuse and without papillæ; also towards the tail, which is long and 
furnished with a digital termination. Vulva a little anterior to the middle of the body.” 
