PARENCHYMATA. 415 



M. Rudolphi, under the name of Echinostoma, makes a division of 

 those species which have a slight tubercle or swelling, anteriorly 

 armed with hooks *. 



HOLOSTOHIA, Nitz., 



Where one half of the body is concave, and so arranged as to act 

 altogether like a cup. Their orifices appear to be similar to those of 

 Distoma. 



They inhabit certain Birds, One species is found in the Fox. In 



Polys TOMA, Zed., 



Or rather Hexastoma ; the body is depressed, smooth, and furnished 

 with six cups, arranged in a transverse line under the posterior mar- 

 gin. The mouth appears to be at the opposite extremity. 



They have been found in the urinary bladder of Frogs, in the 



ovary of Woman, on the branchitie of some Fishes f, and in the 



nasal cavity of certain Tortoises. 



Cyclocotyle, Otto, 



Where there are eight cups, forming an almost complete circle un- 

 der the hind part of the body, which is broad; there is a small pro- 

 boscis anteriorly. 



C. belone, Otto, Ac. Nat. Cur. XI, part II, pi. xli, f. 2. The 

 only species known; it is very small, and was taken on the back 

 of the Belone vulgaris. 

 There is another subgenus that approximates to Fasciola, which I 

 have named 



Tristoma, Cuv. 



The body forms a broad and flat disk ; on the posterior part of its 

 inferior surface is a large cartilaginous sucker, which is only con- 

 nected with the body by a short pedicle, and under its anterior mar- 

 gin are two small ones, between which, and somewhat posteriorly, is 

 the mouth. A circular ramified vessel, the nature of which it is dif- 

 ficult to determine, is observable in the parenchyma of the body. 



T. coccineum, Cuv., a species more than an inch wide, and of 

 a bright red colour, that attaches itself to the branchiae of various 

 fishes of the Mediterranean, such as the Orthagoriscus, Xiphias, 

 &c.| 



* The genus Echinostoma of BlainviUe. 



t Poli/st. inteyerrimum, Rud., pi. vi, 1 — 6, genus Hexathiredia, Trentler; — 

 P. pinguicnla : — P. fhynni, Laroche, Nouv. Bull, de Sc, May 1811, pl.ii, f. 3, genus 

 Hexacotyle of BlainviUe; — Pol. tnidas, Kuhl and Van Hasselt, AUg. Koust. en 

 Latterbode, No. 6, and the Bullet, des Se. Nat. de Feruss., 1824, vol. 11, p. 310. 



X Lamartinitre found a similar but grey one on a Diodon near Nootka- Sound, 

 It formed the genus Caspala, Bosc, Nouv. Bullet, des Sc, 1 81 1 , and that of Phyl- 

 LiNE, Oken, Zool., pi. x. See Journ. de Phys., Sept. 1 787, pi. ii, f. 4, 5. We may 

 unite to it the Tristoma elongatum, Nitzsch, or Nitschia, Bs?r., Ac. Nat. Cur., 

 XIII, pars II, tab. XXXII, f. 1—5. The Axine of the Belone, Abild., Soc. Nat. 

 Hist. Copenh., Ill, p. 2, pi. vi, f. 3, appears to be a Tristoma, wit'a an extremely 

 elongated body, very large posterior suckers, and very small anterior ones. 



