LINGUATULIDA. 7 



t V 



in rimas (quas Diesing injuria bothria rim&formia uniserialia 



nominal) retractiles, ita ut ad cutem abdominalem ipsam affixi sint ; 

 prattrea stigmatum series inter annulos vel inter fimbriarum series 

 in cute (respiratoria organa). Tractus intestinalis simplex, hinc 

 ore, illinc ano terminatus. Systema nervosum constans ex ganglio 

 pectoralij sen subcesophageo, crasso ; annulo cesophageo complete ; 

 interdum 4 gangliis abdominalibus, ex 2 filis nervosis parallelis, 

 catenam nervosam articulatorum exhibentibus exortis. Systema 

 vasorum ex Diesingio adest. Penis filiformis, simplex infra os 

 ex Diesingio, duplex in superficie abdominali (ex aliis) ; testiculus 

 simplex ; ductus deferentes 2. Apertura feminea in apice caudali, 

 vesiculis copulatoriis magnis, spermatozoidia gerentibus. 



Embryones Crustaceis Lernaidis (ex. c. Anchorellis, aut Pycno- 

 gonis] aut rectius Acaris similes. 



For the last reason I have, with Vogt, referred the Linguatula 

 to the Acarina ; Van Beneden places them close to the Acarus 

 folliculorum, as the lowest section of the Arachnida, but not both 

 in one and the same order. 



To me it has long appeared as though the Acarus folliculorum 

 was a Linguatula, a view, however, which was combated by Van 

 Beneden, when I asked for his opinion on the subject. Be this 

 as it may, the relationship between the Linguatulce and the Acarus 

 folliculorum is extremely close. 



As I refer the Acarus folliculorum to the order Acarina, I will 

 do the same with the Linguatulce, which, as the figure shows, are 

 very similar to the Acarus folliculorum, even in the annulation 

 of the abdomen, and, with Vogt, treat the two close together as 

 nearly allied families. 



Deceived by the roundish appearance of the foot-claws, which 

 in certain positions almost form a closed chitinous ring, which 

 certainly, on a superficial glance, has nearly the aspect of a mouth, 

 and by the mobility of these ring-claws, people took these four 

 feet for the same number of oral orifices, so that counting in 

 the true mouth, five such openings were obtained, and the animal 

 received the name of Pentastomum. Reckoning Bilharz's species, 

 we are now acquainted with thirteen in all. Their number, 

 however, would be still further reduced, if Lingualula senata, den- 

 ticulata, emarginata, and tcenio'ides belong to one species. In the 

 mature fully developed state, these animals live in the frontal 

 sinuses and lungs of Mammalia, or in the lungs of various lizards 

 and snakes, but in the immature and encysted state in the 



