LINGUATULA FE110X. ]1 



information, and the number of which we only know from the 

 figure; 2, whether the hooks have an apparatus of support, such 

 as the apparatus described by me, and afterwards by Zenker, in 

 the Linguatula ferox of the rabbit, and clearly recognised by Van 

 Beneden ; 3, whether the points of the hooks have or have not 

 a cover ? From these points alone can we obtain distinctions 

 adapted for the determination of species. If Von Siebold had 

 enlightened us in this fashion, he would have spared the careful 

 Zenker his doubts, and himself that invidious remark at page 331 

 of the seventh volume of his ' Zeitschrift:* 



2. Linguatula ferox = Pentastomum denlicutatum (Zenker), 

 emarginatum, senatum et tcenioides aliorum. 



(Tab, VIII. figs. 1113.) 



Corpus obovato-elongatum, retrorsum attenuatum, apice caudali 

 inter dum emarginatum, venire nunc panum, nunc concavum, dor so 

 convexiusculum, 70 80 annuorum et fimbriarum seriebus ; caput 

 rotundatum ; os ellipticum chitinosum, cujus ad latus utrumquepar 

 unum magnorum aculeorum, qui in cute abdominali chitinoso ap- 

 paratu quodam (stylo retrorsum curvato, antrorsumfarcatim distante 

 et apice chitinoso cavo } qui mucrones hamuli quieti tegit] affixi sunt. 

 Longit. ad 1-J'", latit. antrorsum i'", retrorsum ~" . Habitat in 

 hepate (et quidem inprimis in superficie anteriore lobuli sinistri, 

 rarius in lobulo dextro], rarius porro in renibus, in mesenterio, in 

 tela submucosa duodeni et in tunica mucosa intestini tenuis, hominum 

 qui Europam mediam incolunt. 



The species here referred to was very exactly described by 

 Zenker, who first found it in the human subject, and every one 

 who knows how to determine the Linguatula will see that in 

 Zenker's case young Linguatula feroces are referred to. These 

 Linguatulce are common to man and our herbivorous domestic 

 animals, and if the opinions of Gurlt and myself prove to be 

 correct, they are the immature descendants of the Linguatula 

 tcenio'ides inhabiting the frontal cavities of the dog, which we 

 regard as synonymous with Linguatula denticulata, emarginata, 

 and serrata, and only as different grades of development of the 

 same species. They may reach the closed cavities of the bodies of 

 men in exactly the same way as in the Herbivora. 



Hitherto Zenker has found the animal only inclosed in a firm, 

 even cartilaginous, fibrous capsule, loosely attached to the peri- 



