414 



Festucaria, Schi-. — MoNosTOMA, Zed., 

 Where there is but one of those organs, sometimes at the anterior ex- 

 tremity and sometimes underneatli the same end. Found in various 

 Birds and Fishes*. 



Strigea, Abild. — Amphistoma, Riid., 

 Where there is a cup at each extremity. Found in various Quad- 

 rupeds, Birds,'&c. f 

 - To this subgenus we must probably approximate the 



Caryophyll^us, BL, 

 AVhere the head is dilated, fringed and furnished vinderneath with a 

 bilabiate sucker, not easily perceived. A second and similar sucker 

 has been occasionally seen underneath the tail. 



One species is known, which inhabits various fresh-Avater 

 Fishes, and particulary the Bream %. 



DisTOMA, Retz., Zed., 



Where there is a sucker at the anterior extremity of the mouth, and 



a cup, a little posterior to it, on the venter. 



The species are very numerous, and some are found even in 

 the plaited membrane of the eyes of certain Birds. Others, how- 

 ever, appear to inhabit fresh and salt water. The most cele- 

 brated is 



D. hepatica; Fasciola hepatica, L. ; Schceff., Monog., copied 

 Encyc, Vers, pi. Ixxx, 1 — 11. It is very common in the hepatic 

 vessels of Sheep, but is also found in those of various other 

 Ruminantia, and of the Hog, Horse, and even of Man. Its form 

 is that of a small oval leaf, pointed posteriorly, with a narrowed 

 portion anteriorly, at the end of which is the first sucker, wliich 

 communicates with a sort of esophagus, from which arise canals 

 that ramify throughout the body, conveying the bile on which 

 this anim.al feeds. Behind the sucker is a little retractile tenta- 

 cidum, which is the penis, and posterior to that, the second 

 sucker; extremely flexuous vesiculae seminiiles fill up the centres 

 of the leaf. The ovary, which is found in every individual, is 

 set in the intervals of the intestines, and the ova issue through a 

 fiexiious canal that opens exteriorly by a small hole by the side 

 of the penis. These annimals enjoy a mutual coitus. 



The species that infest Sheep become greatly multiplied when 

 they graze in low and wet grounds, rendering them dropsical, and 

 finally killing them §. 



* Ruil., Hist., II, p. 325, and Syn. 82; the HyposTOMA, Blainv., are a division 

 of the same, with a depressed body, and cups placed under the anterior extremity. 

 Van HassL'lt and Kuhl have discovered two new species in the Ckdoaia midas, Bullet, 

 of FLn-u==., 1824, vcl. II, p. 311. 



t Rud., Hist., p. 340, and Syn., p. 87. 



X Id., Hist., pars II, y, and Syn., p. 127. 



§ For the other species see Rud., Hist., II, pars I, p. 357, and Syn., 92. For 

 their organization see OLservationes AnaL de Distomate hepatico et lanceolato of Ed. 

 Mehlis, Gotting., 1825, in folio. 



