On a Remarkable New Species of Porocephalus (P. pomeroyi, sp. n.) from the Fore-gut of a Nigerian Cobra

Extract

In August, 1920, Dr Andrew Balfour, C.B., C.M.G., Director of the Wellcome Bureau of Scientific Research, received from Mr A. Pomeroy, F.E.S., Official Entomologist in South Nigeria, a tube containing some parasites from the “fore-gut” of a Cobra (Naia nigricollis Reinh.) from Ilaro, South Nigeria. Dr Balfour kindly handed these specimens to me for examination. The specimens were few in number, comprising only ten Nematodes and the two examples of Porocephalus described in the present Note. One of these examples at once attracted my attention by reason of its remarkable external form (Text-figure 1, A). I have consulted most of the available literature dealing with Porocephalus and the figure which, so far as I have discovered, most nearly approaches that of the present specimen is that of P. annulatus Baird, supplied by Shipley (his Text-figure 5, p. 59) in his memoir on the Linguatulidae. From my reproduction of Shipley's figure (Text-figure 1, C) it will be seen that Porocephalus annulatus, like the new species nowto be described, has a very narrow “neck,” but whereas in P. annulatus this neck is very short, in the new species it is comparatively very long; moreover, whereas in P. annulatus the cephalo-thorax (prosoma) is not longer than broad (or only slightly so in some specimens) and the first annulus of the “abdomen” (opisthosoma) is certainly no larger than succeeding annuli, in the new species the prosoma is roughly three times longer than it is broad and the first annulus is at least twice the size of the third at any succeeding annulus.