30 Description of a Species of Worm 
species of the Pentastoma are enumerated by Rudolphi, and figured 
in his admirable illustrations, Plate X. The nearest approxima= 
tion which the present worm exhibits to any of these, is the Pen- 
tastoma Tenioides, Fig. 14, 15. Plate X. the original specimens of 
which were found in the frontal sinus of the wolf, (canis lupus.) 
The Pentastoma Tzenioides is found also in the frontal sinus of the 
dog, (canis vulgaris ; ) and, according to Greve, in the ethmoidal. 
cells of the mule. Another species, the Pentastoma Denticulata, 
has been found in the frontal sinus of the goat, (capra hirecus and 
capra Americanus ;) but, as far as I know, this is the first of the 
genus Pentastoma which has been described by any writer as found 
in the frontal sinus of the sheep. 
The general characters of this worm are as follows: Body ob- 
long, annular, sub-depressed, curved, and tapering slightly towards 
its head, and abruptly towards its tail, which terminates in an ob- 
tuse point, in the centre of which is situated the anus. Head large, 
obtuse, with five orifices ; the central one circular, and the ethers 
awl-shaped: the abdominal viscera commencing a line from the 
head, and terminating about two lines from the tail. The belly is 
rather depressed, and the epidermis thickish, with the annulations 
distinctly continuous. The back is tumid, -and the membrane ex- 
tremely pellucid; the annulations in the upper extremities of 
which are nearly invisible, becoming more distinct as they appreach 
the tail, under which the convolutions of the oviducts, (which are 
of a flesh colour,) can be distinctly traced throughout their whole 
length, with the intestinal canal running above along the left side, 
disappearing among the folds of the oviducts, about 3-4ths of an 
inch from the tail, and then re-appearing, and crossing them till 
they are no longer seen. From the sides of the abdominal cavity 
the worm is quite depressed, and the edges along its whole length 
serrated. Length 2 inches; breadth 3-8ths ; colour cream white. 
The Distoma Hepaticum is a species frequently found in the li- 
vers of sheep, and the Ceenurus Cerebralis, a species of the Hyda- 
tid, is also found occupying the cavities of the brain of the same 
animal. The present worm, however, has no similarity to either 
of these species. 
It is certainly a singular question, and one of some interest, How 
this worm has been generated in the frontal sinus of the sheep? It 
is a cavity, one would imagine, completely excluded from all ex- 
traneous communication ; and if any circumstance could favour the 
idea of spontaneous or equivocal generation, this is certainly a 
strong one. 
Unfortunately Iam unable to give any description of the appear- 
ance of the frontal sinus where this animal was found lodged ; whe- 
ther it was compact and impervious on all sides, or whether the 
sutures of the skull were pervious, or any, the least opening was 
found communicating with the interior of the cavity. But neither 
in this case, nor in similar ones, are we to assume the theory of 
spontaneous generation as a fact established, because we find it im~ 
