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Show 250 MR. A. E. SHIPLEY ON ENTO-PARASITES. [Apr. 18, Larval forms :- Pentastomum subcylindricum Diesing. Pentastomum clavatum Wyman. Three specimens, the largest measuring 11 cm., were taken from the lungs of a Zamenis mucosus Boul., a snake which occurs from Transcaspia and Afghanistan, across Asia, to the sea-board of China and to the Malay Peninsula and Java. In my " Attempt to revise the Family Linguatulidae " (Archiv. Parasit. i. 1898, p. 52) ] have given a list of the numerous hosts which harbour this form. There were also some encysted larval forms coiled up in pieces of the liver or in fragments of membranous tissue which looked like mesentery. In the relationship of the mouth to the hooks and in the general appearance of the head they resemble P. crotali, but they have an unusual number of annuli, quite fifty. These annuli in the Pentastomida are obviously very variable characters, and they do not correspond with any true segmentation. It has sometimes occurred to me that their number depends upon the closeness of the coil in which the larva lies. These larvae, at any rate, were very closely coiled. POROCEPHALUS MONILIFORMIS (Diesillg). Pentcistoma moniliformis Diesing. A single specimen, somewhat injured, from Python sp. The club-shaped head and the moniliform character of the segments and the pointed tail were very marked. The number of segments, counting the terminal joint, was 28, thus agreeing with Diesing's figure *. POROCEPHALUS HERPETODRYADOS, 11. sp. Diagnosis.-Length averaging about 10 cm., breadth 2-5 to 3 mm. in the body, in the head 4‘5 to 5 mm. About 50 annuli. There are no depressions between these, or hardly any; the body is smooth, and although the segments are quite distinct they pass smoothly into one another like the nodes of an Equisetum. The head is separated from the body by a distinct neck which is faintly annulated, as is the posterior part of the head. The four hooks are in one straight line, and the posterior border of the oval slit-like mouth is on a line with the posterior border of the hooks. The hooks are simple, there is no accessory booklet. There are four conspicuous papillae just in front of the hooks. The presence of a distinct neck associates this species with P. annulatus Baird and P. tortus Shipley, but the neck is not so distinct from head and body as in the former, or so short as in the latter of these two species. The hooks, which have no accessory booklet, have a well-developed flange as in P. subidiferus Lckt. and many others. The hooks are strongly curved, and under the * Denk. Ak. Wien, xii. 1856, p. 31. |