NOTICES OF IRISH ENTOZOA. 71 



The head found in the tumors before mentioned, and when 

 the neck or pedicle did not pierce the intestine, was as large 

 as in the fully-developed specimens; but supposing the young- 

 animal to be attached to the mucous coat, it must be obvious 

 that a small proboscis-like head would answer better, as giv- 

 ing a more penetrating and surer hold than an expanded bulb. 

 Now Rudolphi describes the head of the smaller specimens 

 of Ech. sphcerocephalus as if it were really a proboscis, and 

 makes no mention of a head at all. "Minorum : Proboscis 

 globosa vel sub-globosa (antica parte turn minus convexa), 

 echinomm mediocrium seriebus plurimis dense armata." — 

 ' Syn.' p. 670. Of the larger specimens he says, — "Magno- 

 rum : Proboscis nulla, sed bulla terminalis magna, rotunda, 

 parum armata." — f Syn. ' p. 471. Now if Ech. Jilicollis and 

 Ech. sphcerocephalus be the same, the peritonceum and not 

 the mucous coat is the more natural situation of the head, 

 which I would infer from this, that Ech. Jilicollis is by no 

 means unfrequent, whereas Ech. sphcerocephalus is only 

 known I believe through the medium of the specimens from 

 Brazil. When therefore the developement of the animal 

 commences in the intestinal cavity, although the head may 

 be so constitutioned as to adapt itself to that locality, yet the 

 more natural developement into a ball will occasionally mas- 

 ter the tendency to accommodation ; and hence we find that 

 at least in one of the small specimens examined by Rudolphi 

 the head did not assume a proboscideal form. " Unicum 

 tantum specimen acque parvum proboscidis loco bullam mag- 

 nam seriebus longitudinalibus armatam obtulit." — ' Syn. ' p. 

 671. 



The head of Ech. Jilicollis is not truly globular, but is of 

 the form of an oblate spheroid ; and when the side of it is re- 

 moved by a vertical section, a white strong pillar is seen, 

 standing in its centre, and continued into the umbo, while a 

 considerable interspace (containing a fluid ?) lies between it 

 and the outer walls. It thus bears a considerable resemblance 

 to the vertical section of the capsule of some mosses, espe- 

 cially of Splachnum. In the central pillar I could find no 

 trace of a proboscis. The lateral bandelettes of Cloquet are 

 very conspicuous on opening the body of the animal ; they 

 are two round, firm cords, about four lines long, and having 

 their extremities free, while their base is firmly attached to, 

 or rather continuous with, the root of the neck. 



Belfast, Dec. 30th, 1838. 



