Dr. O'Biyen Belliugham on Irish Entozoa. 103 



Genus 7. Strongylus. 

 (Derived from arpoyyvXos, teres.) 

 Body cylindrical and elastic, attenuated at each extremity. Mouth 

 orbicular or angular, simple or provided with tubercles. Anus sub- 

 terminal. Penis a simple filament, issuing from the centre of a 

 kind of pouch, which terminates the body of the male. 

 This genus was established by jMliller, and has been adopted 

 by zoologists since. The species are numerous : Rudolphi enu- 

 merates thirty-eight, of which fifteen are doubtful ; they occur in 

 mammaha and birds, rarely in reptiles, and are not found in fish. 

 They occur in almost every part of the body, but inhabit princi- 

 pally the trachea, oesophagus, or tubercles connected with these 

 parts, the stomach and intestines ; they are sometimes contained 

 in anemismal tumom's of the mesenteric artery in the horse and 

 ass. The species have been arranged by Rudolphi in his ' Sjti- 

 opsis' under three subdivisions. 



Ore orbiculari tioduloso sen papilloso. 



fTubercles in oesophagus of teal (^Anas 



I Creccci). 

 , o J f r-f J Tubercles in oesophagus of pintail (Anas 



"" I acuta). 



I Tubercles in oesophagus of shoveller (Anas 



[^ Clypeatd) . 

 2. contortus. Small intestine of sheep (Ovis Aries). 



Ore nudo. 



{Small intestine oi rabhit (LepusCu- 

 SmTtntestine of hare (Lepus ti- 

 midus). 



mity, and they lived in water for some time. Their length is six to 

 seven lines, they are thicker posteriorly than anteriorly, and when 

 recent were quite pellucid, so that the whole tract of the alimentary 

 canal could be traced through the parietes ; this was straight, narrow 

 anteriorly, and becoming wider posteriorly. 



The mouth is orbicular and prominent, with four tubercles sur- 

 rounding it, which varied in shape when the animal was alive ; hence 

 this species must be referred to the second division in Rudolphi's 

 arrangement, in which the mouth is papilla^}^ The anus rounded, 

 and a little in front of the caudal extremity. The part which might be 

 called the neck is armed with recurved hooks ; the anterior third of 

 the body is also armed with four rows of much smaller hooks or 

 spines, which are very numerous and close anteriorly ; they diminish 

 in number, and gradually disappear near the junction of the anterior 

 ■with the middle third of the body. The caudal portion of the body 

 is double the thickness of the anterior, and its extremity is conical. 



