348 CATALOGUE OF THE ENTOZOA 



Genus 2. —Trichosoma. 



(Derived from t^'I, capillus.) 



Body cylindrical and elastic, of moderate length, very slender towards 

 the anterior extremity, and insensibly enlarging posteriorly. Mouth 

 terminal, punctiform. Male organ a simple filament contained in a 

 sheath. 



This genus was established by Zeder, under the name of 

 Capillaria. The species are most common in birds, next in 

 the Mammalia ; they are very rare in reptiles and fish ; they 

 inhabit the stomach, the small and large intestines, some- 

 times the urinary bladder. The species of the genus Tri- 

 chosoma are all exceedingly small, and resemble each 

 other very closely (almost the only difference being a Httle 

 greater or less length or thickness of the body), and as male 

 and female are not always found together, it is very difficult 

 to determine the species accurately ; in fact, of the twenty- 

 two species which Rudolphi has enumerated, sixteen are 

 doubtful ; and of thirteen species which I have met with 

 nine are doubtful. 



TRICHOSOMA. 



1. Trichosoma o&^MSMTO ? ,. Ctgca of homcd owl. 



2. „ infiexum? Small intestine of missel thrush. 



«3. „ longicolle? Small intestine of domestic fowl. 



4 ,. f Urinary bladder of dog. 



» ^"^^ {Urinary bladder of fox. 



Species duhiee. 



6. Trichosoma ...,» Urinary bladder of wild cat. 



6. „ Small intestines of weasel. 



lines in length, colour white, body slender, and of the same diameter 

 throughout. Anterior and posterior extremity rounded, mouth obscurely 

 orbicular ; a slight prominence near the posterior extremity, at which the 

 anus appeared to open. 



C. This species I have met with upon several occasions in the cavity of 

 the abdomen of the commonhumblehee {Bombm terrestris), and sometimes 

 in very large numbers; they lived and moved about in a watch glass con- 

 taining water, for a considerable time ; they are cylindrical, some are 

 smaller than others, and in these the posterior extremity is very slightly 

 curved, in the larger (which probably are females), this part is straight. 

 They are so small as to be hardly visible without a lens, and in consequence 

 of this I have not been able to succeed in seeing the shape of the mouth ; 

 hence they may probably eventually turn out to belong to some other 

 genus. 



