506 ENTOZOA. 



Strongylus, Mull. 



Here the body is round. In some of these Strongyli the mouth is ciliate or 

 dentated. Such is that which infests the Horse, or the 



S. equinus, Gm. It is also found in the Ass and Mule. 



The mouth of others is merely surrounded by tubercles or papillse. Such 

 particularly is the 



S. gigas, Rud., the most voluminous of all known intestinal Worms; it 

 is upwards of two or three feet in length, and as thick as the little finger. 

 The most singular circumstances attending this Strongylus is that it is most 

 usually developed in one of the kidneys of various animals, such as the 

 Wolf, Dog, Mink, and even Man, where it lies doubled up, distending that 

 organ, destroying its parenchyma, and probably occasioning the most ex- 

 cruciating agony to the animal in which it resides. It sometimes inhabits 

 other viscera- Its usual colour is a beautiful red; the mouth is surrounded 

 with six papillse; the intestine is straight and transversely rugose, the ovary 

 simple, three or four times the length of the body, communicating exteriorly 

 by a hole a little distance posterior to the mouth, and, as it appears, open 

 at the other extremity. An extremely attenuated white thread that extends 

 along the abdomen is considered by M. Otto as the nervous system. 



Lern^a, Lin. 



The internal and external organization of the body is nearly the same as in 

 the Nematoidea, but it is prolonged anteriorly by a corneous neck, at the 

 extremity of which is a mouth variously armed and surrounded, or followed 

 by productions of different forms. This mouth and its appendages are in- 

 sinuated into the skin of the gills of fishes, and fix the animal there. The 

 Lernese are also distinguished by two cords, sometimes moderate, and at 

 others very long, or even much doubled, that are pendent from the sides of 

 the tail, and which may possibly be ovaries. 



L. branchialis, L. The most known species; it attacks the Codfish and 

 other Gadi, and is from one to two inches in length. Its mouth is surround- 

 ed by three ramous horns, which, as well as the neck, are of a deep brown. 

 Its more inflated body is bent into an S, and the two cords are contorted 

 in a thousand different ways. Its horns become rooted, as it were, in the 

 gills of fishes. 



ORDER II. 



PARENCHYMATA. 



The second order of the Entozoa comprises those species in 

 which the body is filled with a cellular substance, or even with a 



