6 ANIMAL PARASITES. 



immature 6, in maturo 8 articulatis, formd diver sis simis, abdomini 

 insertis, aut nullis (in Linguatulis maturis sine pedibus, in imma- 

 turis vero cum pedum incremcnto) ; cute magis minusve molli, 

 tantum in Oribatidis (plant-mites) fragili, dura et fere vitrea ; 

 organis mauducatoriis formatis ex proboscide inter dum articulata, 

 re- et pro-tractili, in qua aculei 2 acuti et gladiformes reconditi 

 sunt ; tubo intestinali proboscidem secuto, appendicibus multis et 

 lateralibus instructo ; oculis 2 in anteriore cephalothorace, aut 

 nullis (in Acaris sub cute parasitantibus) ; organis antennaeformibus 

 binis ad utrumque proboscidis latus, plerumque ex 5 articulis com- 

 positis, et formd variantibus (exc. in Hydrachnidis aculei- aut 

 ancorce-formibus, aut valvaformibus, dentatis in Ixodidis, aut fusi- 

 formibus in Oribatidis, aut setosis in Bdellidis et Opilionidis. fyc.) ; 

 organis respiratoriis tubulosis, ramificatos fasciculos formantibus et 

 ex stigmatibus 2 lateralibus, quce plerumque interpedes posita sunt, 

 exortis ; in inferioribus Acarinorum familiis nullis ; corde nullo. 

 Parasita rarissime vivipara, plerumque ovipara ; in juvenili statu 

 6 pedibus instrucla, ex quo in maturum statum 8 pedibus ornatum, 

 tempore quodam in otio, sive nutrimento, et interdum in tenebris et 

 cystidibus quibusdam peracto, transeunt. 



First Family LINGUATULIDA = PENTASTOMA. 



Synon : Tcsnia ; Distoma et Porocephalus ; Tetragulus ; Echi- 

 norhynchus ; Halysis ; Prionoderma ; Polystoma et Pentastoma ; 

 Monostomum. 



From these names it will be seen at once \vhat various places 

 in the system have been assigned to this worm. Kudolphi re- 

 garded them mostly as Trematoda; Diesing places them with the 

 worms, as Acanthotheca. We pass over his views, which have 

 been completely refuted by Van Beneden, and refer them, with 

 the latter, to the Articulata, on account of their transversely 

 striated muscles. 



Animalia solitaria, alia mascula, alia feminea ovipara. Corpus 

 vermiforme, elongatum, depressum vel teretiusculum, ex articulis 

 permultis compositum, Iceve vel fimbriatum seu aculeatum ; caput 

 corpore continuum, fere cephalothoracicum ; os anticum, chitinosum, 

 ad cujus utrumque latus hamuli bini aut semilunares, aut ungui- 

 formes, simplices aut magis compositi, in exemplaribus juvenilibus 

 ad pedes breves, fere inarticulatos affixi, in exemplaribus maturis 



