of Edinhurgh, Session 1882-83. 
219 
3. On a new Entozoon {Pentastomum protelis) from the Mes- 
entery of Proteles cristatus, Sparrmann. By W. E. Hoyle, 
M.A. (Oxon), E.R.S.E., Naturalist to the “ Challenger ” 
Expedition Commission. 
{Abstract.) 
The entozoon, which is a new species of Pentastomum, was 
found by Professor Morrison Watson in a 
male Proteles cristatus which had died in the 
Zoological Society’s Gardens. 
The parasites, to the number of about ten, 
were found enclosed in cysts in the mesentery, 
and presented the appearance shown in fig. 1. Fi^- 1. General appear- 
ance of the encysted 
In every instance except one, the ventral parasite, 
surface of the animal formed the convexity of the curve. 
The species may he characterised as follows ; — 
Pentastomum protelis, n. sp. 
Body, cylindrical in the anterior half, slightly tapering posteriorly, 
terminal segment obtusely pointed. Eo clear distinction between 
cephalothorax and. abdomen. Head hemispdieroidal, equal in diameter 
to the body. Mouth furnished with a papilla, perhaps a protriisihle 
proboscis. Stigmata arranged in numerous irregidar roivs on all the 
segments. Male, 13-17 mm. in length, ivith 16 or 17 animli. 
Female, 20-25 mm. in length, with 18-22 annuli. Habitat, the 
mesentery of Proteles cristatus, enclosed in a connective tissue cyst. 
The above description being taken from specimens which, from 
their encysted condition, were presumably immature, must be re- 
garded, to a certain extent, as provisional. 
The appearance of the ventral surface of the head is shown in 
fig. 2. In one or two examples the posterior ter- 
minal segment aptly fulfilled the expression used 
by Diesing in describing another species, “ cute 
externa in forma praeputii,” but this was by no 
means constant. 
The species bears a close resemblance to P. Fig. 2. Ventral sur- 
polyzonum, Harley, but is distinguished from it 
by the number of segments, which, in the case of P. polyzonum. 
