350 CATALOGUE OF THE ENTOZOA 



fish. The genus is not numerous in species. Rudolphi has 

 arranged them in two subdivisions ; our native species belong 

 only to one of these subdivisions. 



TRICHOCEPHALUS. 



1. Trichocephalus dispar F Large intestines of man. 



2. „ crenatus G C^ecwm of pig. 



3. „ nodosus Ccecum of mouse. 



»» 



Genus 4. — Oxyvrus. 



(Derived from o^ug aeutus, and Oi'f « cauda.) 



Body cylindrical and elastic, the posterior extremity subulate in the fe- 

 male ; mouth orbicular and terminal ; male organ contained in a sheath. 



The genus Oxyurus was established by Rudolphi ; it con- 

 tains a very small number of species, only three being enu- 

 merated by Rudolphi in his ' Synopsis.' The species inhabit 

 the large intestines of the Mammalia, and have not been 

 found in either birdsj reptiles, or fish. 



OXYURUS, 



1. Oxyurus curvula H Large intestine of horse. 



2. „ amhigua I Ceecum of rabbit. 



F. The Tnchocephalus dispar has been longer known than any other 

 species in the genus ; and although stated by several writers to be rare in 

 these countries, in the course of my experience I have found it by far the 

 most common species inhabiting the alimentary canal of the human sub- 

 ject : I have examined the intestinal canal of eighty-six individuals, who 

 died in St. Vincent's Hospital, Dublin, of various diseases, and whose ages 

 varied from three years to seventy; and in seventy-seven out of the eighty-six, 

 I found a larger or smaller number of this species ; sometimes only one or two 

 existed, sometimes they were in considerable plenty; the largest number I 

 have met with in the same individual, was one hundred and nineteen : 

 sometimes they were attached to the mucous membrane, more commonly 

 they were free ; they almost always inhabited the large intestine, particu- 

 larly the c(Bcum ; I have, however, met with them in the small intestine. 

 The male appears to be as common, or perhaps more common, than the 

 female, which is contrary to what happens in most other genera of Nema- 

 toidea. 



G. This species resembles pretty closely the Trichocephalus dispar ; the 

 capillary portion of the animal is, however, a little longer, and the sheath 

 of the penis has a somewhat diiFerent shape from what it has in that spe- 

 cies. 



H. The Oxyurus curvula is noticed in Pennant's British Zoology, under 

 the name of Trichocephalus equi ; it is the largest species of the genus, 

 inhabiting the great intestine of the horse, and is not at all uncommon. 



I. I have found the Oxyurus amhigua in great numbers in the ccBcum 

 of the common wild rabbit ; the females arc double the length of the 



