BARKER AND MACALISTER ON ECHINORHYNCHUS I>ORRIGENS. 293 



A paper was then read — 



On Echinorhynchus porrigens. By John Barker, H.D., E.R.C.S.I., 

 M. R. I. A., E. R. G. S. L, and A. Macalister, L. K. Q. C. P., 

 L. E. C. S. I., E. R. G. S. I. 



This animal is so rare — so seldom, too, is its usual host or living resi- 

 dence examined, and so remarkable is it in its form and structure — that 

 no apology is needed for presenting it to your notice, even had it been 

 well described before. The figures of it in the best references are but 

 copies of one another, and unlike our animal in some respects. The 

 Echinorhynchi are acanthocephalic Entozoa ; and their name, although 

 it graphically illustrates their chief feature, does not accurately repre- 

 sent the structure. Perhaps Ealcatorhynchus would be more appro- 

 priate. We must congratulate ourselves that we are not the host of 

 such a monster, with such a formidable proboscis as has been well re- 

 presented in the diagram by Dr. Macalister. Let us not boast, how- 

 ever ; species of Echinorhynchus have been found in the Simiadae, in the 

 Inuus sylvanus, and Midas rosalia ; and we do not know how soon they 

 may be discovered in us in these days of animal progression. The spe- 

 cies of Echinorhynchus already known number upwards of a hundred, 

 and are chiefly found in birds and fishes, although they have been re- 

 cognised in all classes of vertebrate animals. One of the largest, E. 

 giyas, inhabits the hog, and sometimes attains the length of a foot. JE. 

 porrigens is seldom more than six inches long. The specimens on the 

 table are not more than two inches and a half, but these have been 

 much contracted by the spirit of wine in which they were preserved. 

 This species is said to inhabit the Eider Duck {Anas mollissima), as well 

 as the Balanoptera rostrata (lesser rorqual whale) — a specimen of which 

 has lately undergone a careful examination by Drs. Carte, Macalister, 

 and myself, at the College of Surgeons. John Hunter was, I believe, 

 the first to direct attention to this animal, and subsequent authors have 

 derived their knowledge either from him, or from specimens in the 

 Berlin collection, preserved by "Walter, and described by Rudolphi. The 

 Echinorhynchi are vermiform, often curved on themselves, marked 

 with tolerably regular transverse folds, and have a retractile proboscis, 

 armed with recurved hooks. They have neither mouth nor intestinal 

 canal, possess a nervous ganglion, and are of separate sexes. The spe- 

 cimens before us were found in the duodenum of the whale (Walter 

 states that the specimens put up by him were in the jejunum), and their 

 presence was well indicated by large fleshy papilla?, which were found 

 prominent in the mucous membrane of the intestine. The openings of 

 these papilla? were all directed downwards in the course of the intes- 

 tine, and led to a tubular cavity, situated obliquely between the mucous 

 and muscular coats, in which were contained the head and a considera- 

 ble part of the entozoon, and also some whitish grumous matter. One 

 of these papillae is shown opened, with the animal in situ, in the spe- 



