340 
Porocephalus pomeroyi n. sp. 
of this suggestion is to be found in their relative dimensions. The female 
specimen (64 mm.) was slightly more than five times as long as the male. 
I his is also the case in other species of Porocephalus. Thus Spencer 1 states 
that m P. teretiuscuius the female is nearly five times as long as the male5 
Miss Hett 2 similarly mentions that in Raillietiella a female measures 40 mm. 
and a male 10 mm.; Harley 3 says that the largest female specimen (found in 
the lungs of an Egyptian Cobra) of “Pentastoma annulatum” was 4 3 inches 
long and a male (found in the nasal fossa of the same Cobra) 1J inch long; 
m P . lari, Megnin, the female measures 6 cms. and the male about 1 cm., and 
in most other species of Porocephalus the female is at least twice as long as 
the male. 
Against this view that these two specimens are a female and male of the 
same species are the facts that they are of very different shape externally, 
that the female has 32 annuli and the male 37, and that the hooks are perhaps 
slightly different in form. However, the exact number of segments which 
compose the opisthosoma cannot be regarded as a safe character on which to 
found specific distinctions, nor are minute differences in shape of the hooks 
of more value, and I think it is highly probable that the two specimens of 
Porocephalus above described are the female and male forms of the same 
species. If this be so, then these two specimens present the most marked 
form of sexual dimorphism yet discovered in the Linguatulidae. 
Note on the Habitat of Porocephalus pomeroyi. 
By fore-gut I assume Mr Pomeroy to mean the anterior part of the 
intestine, and not the mouth-cavity, throat or oesophagus of the Cobra. 
This assumption is borne out by the fact that with the two Porocephalus 
individuals ten Nematodes (the smallest 12 mm. long) were found. I need 
hardly point out that this situation, if correctly stated 4 , is an unusual one, 
the vast majority of Linguatulids being found either in the frontal sinuses, 
nasal cavity, trachea, lungs or body-cavity or in the substance of certain 
organs (muscles, liver, kidney, spleen) of Vertebrates other than fishes. 
Postscript. (8. X. 1920): Mr Pomeroy informs me that the two specimens of Poro¬ 
cephalus above described “appeared to be joined together by a ligament and were not 
separated when I removed them from the snake.” Mr Pomeroy encloses a rough sketch 
from memory of the way in which the two specimens were united, from which it would 
appear that a filamentous connection extended between the posterior sexual aperture of 
the large female and the exterior sexual aperture of the small male; this connection seems 
to prove that the pair belong to the same species. 
Mr Pomeroy also confirms his previous statement that the pair were found in the 
intestine “ about the middle of the snake, and not as I have found them before in the first 
part of the fore-gut.” 
Balchvin Spencer (1893), Quart. Journ. Micr. Science, xxxiv, 1. 
2 Hett, M. L. (1915), Ibid, lxi, 185. 
3 Harley, G. (1857), Proc. Zool. Soc. London, Part 25, p. 115. 
Wyman (Post. Soc. Nat. Hist,., Sept. 17, 1845) mentions Porocephalus armillatus as occurring 
in the intestines of a Python. 
