62 Proceedings of the Royal Irish Academy. 



J XL — On two J^ew Species of Pentastoma. By A. Macalistee, M.B., 

 Professor of Comparative Anatomy, Dublin University. (^Yith 

 Plates 2 and 3.) 



[Eead November 9, 1874.] 



In dissecting a specimen of Boa imperator brought home by Dr. 

 Armstrong (of the Army Medical Service) from South America, 1 

 found in the lung and peritoneal cavity about six specimens of a Penta- 

 stoma. It resembles the P. proboscideum of Rudolphi, which has been 

 found in the allied species Boa constrictor as well as in Epicrates 

 angulifer, Lachesis sp., and a species of Bothrops, but differs specifically 

 from the type of P. prohoftctdeutn, as well as from the subtypical varieties 

 of that species, P. clavatum of Wyman and P. subct/lindricu»i of Diesing. 

 The specimens measure — the females 45-57/«»i, the males 

 19-22mm in length. In breadth the females are 3-3mm at the head, 

 1"27-2'28otw at the narrowest point which is the hinder fourth, and 

 about l'30-2-5mm at the tail. The males in width are a little less. The 

 body is annulated posteriorly, but for the cephalic half the rings are 

 not very clear ; each ring consists of a wide flat belt of surface, with 

 a slightly chilinized epidermis, and a thicker hypodermis, than that in 

 the intersegmental zone. The head is convex, rounded posteriorly and 

 flattened below ; in front and below it projects forward as an anterior 

 firm ridge, with a thick chitinous integument, a little under whose 

 edge are the two pairs of hooks. The surface of the body is finely and 

 rather irregularly ridged in some places, but is devoid of either pro- 

 cesses or bristles. On the back of the vertex, 7mm from the front, there 

 is a small, raised, flatly-conical, median wart, slightly radially ridged 

 around its margin, but imperforate ; in front of this are five or six 

 other smaller wartlike surface-eminences. 



The two pair of hooks are sharply curved, acute, hollow, the inter- 

 nal cavities extending to near their points : they have each an inferior 

 basal spur, elongated anteriorly for muscular attachment; each has also 

 a bilaminar basipodal process, to which also the muscular lamellae are 

 attached. These hooks are dark brown, and finely longitudinallj- 

 striated in some places; each hook is about 0-6-0-28mm in length. 



The mouth is elongated, elliptical, with a smooth chitinous peri- 

 stomial ring, on the level of the bases of the median hooks ; it leads 

 into the scarcely subdivided digestive tract. The oesophagus is thin- 

 walled, with no proper glandular wall, other than its thin lining 

 epithelium ; it passes over the receptaculum seminis, and between the 

 two cirrus pouches. It dilates feebly into the stomach, an elongated 

 sac with longitudinal glandular ridges on its wall, and here and there 

 papillary processes. The gland cells are spheroidal, deep brown in 

 colour, and give the digestive canal a deep hue, rendering it visible 

 through the body wall. The lowest part of the digestive canal, or the 



