INDIGENOUS TO IRELAND. 347 



tinal canal. The generic characters are taken principally 

 from the shape of the mouth, or from the disposition of the tu- 

 bercles which surround it ; the absence or presence of lips, &c. 

 The genera in this order are found in all classes of ani- 

 mals ; they inhabit almost every organ, but most frequently 

 the alimentary canal. 



Genus I. — Filaria, 



(Derived from Filum^ a thread.) 



Body long, cylindrical, and elastic, nearly of equal diameter throughout; 

 mouth orbicular. Male organ a simple spiculum. 



This genus was established by MilUer, and has been 

 adopted by Rudolphi ; the species inhabit cellular membrane 

 in every part of the body, very rarely the alimentary canal ; 

 they are not uncommon in Mammalia, birds, and fish, they 

 are less common in reptiles ; they occur also in invertebral 

 animals, particularly in the larva of Lepidoptera, and in 

 some Coleoptera. 



The Filaria have been arranged by Rudolphi in two sub- 

 divisions, according as the mouth is simple or papillary and 

 labiate. 



FILARIA. 



Ore simplici. 



J. YiLXRiA attmuata Cellular membrane in abdomen of peregrine 



falcon. 



Species duhiee. 



2. Filaria A PeritoneBum of red gurnard. 



3. „ B PeritoncBum of mullet {Mugil capito.) 



4. „ C ? Abdominal cavity of bee {Bombus terrestris.) 



A. This species of Filaria (which does not appear to have been described) 

 occurred under the peritonceum of the common red gurnard {Trigla pini.) 

 The specimens which I possess are from three to four inches in length, and 

 about the thickness of strong thread, the colour white, body cylindrical, 

 and of the same diameter throughout. Anterior extremity obtuse and 

 rounded, posterior acute. Mouth orbicular and very small. In removing 

 them, some ruptured, and allowed the ovaries and intestinal canal to pro- 

 trude. 



B. This species (which also appears not to have been described), oc- 

 curred in the peritoneum of the common grey mullet {Mugil capita) : they 

 were so imbedded in this membrane that it required considerable trouble 

 to remove them, and some portion of the membrane continued to adhere 

 to them, which rendered their examination difficult; they are about 4|^ 



Vol. IV.— No. 34. n. s. 2 u 



