326 MR. R. OWEN ON THE ANATOMY OF LINGUATULA T/ENIOIDES. 
the assimilative organs are not merely excavated in the parenchyma of the body, but 
consist of tubes with well-organized parietes, which lie loose in a distinct abdominal 
cavity, as in the Nematoidean and Annulose worms. It is owing to this structure that 
Cuvier has separated Linguatula (the Pentastoma of Rudolphi) from among the Vers 
parenchymateux, or Sterelmintha, and placed it in the Celelminthic division, or Vers 
cavitaires. Rudolphi, however, remaining uncertain as to the structure of the digestive 
organ, is unwilling to adopt this arrangement ; he observes! : ‘‘ Pentastomati Cuvirrvs, 
vir summus, tubum intestinalem rectum adscribit, ideoque et ob systema nerveum Ne- 
matoideis addit ; specimen autem, quod dissecui, me dubium reliquit ; ab anteriori etiam 
parte duo intestinula czeca? sunt complicata, posteriora versus canalis tenuis albus 
decurrit sed non cuti affixus, qualis Nematoideis esse solet, sed undique ovariis circum- 
volutus, neque ejusdem fines cognoscere potui ; quam ob causam rem in medio relin- 
quam.” 
In the specimen here described, the tube, which Cuvier rightly considers as the 
alimentary canal, was readily traceable from its commencement to its termination. It 
begins at the central foramen, or true mouth, and runs straight to the opposite extre- 
mity of the body, terminating immediately above the orifice of the genital tube. It is 
concealed in the greater part of its course, as in many of the Nematoidea, by the tor- 
tuosities of the oviduct ; but on separating the coils of the latter its course may be 
satisfactorily ascertained. The esophagus is one third of a line in length, and opens 
into a suddenly dilated canal, which continues with little variation of diameter to the 
anus: the coats of the canal are thin, of a white colour, and not transparent. 
With respect to the generative organs, Cuvier observes: ‘‘ L’intestin est droit ; les 
vaisseaux génitaux longs et entortillés. Les uns et les autres ont leur issue a l’extré- 
mité postérieure.” M. de Blainville also observes: ‘‘ Les oviductes sont longs et en- 
tortillés.” Rudolphi, in the ‘Synopsis Entozoorum’, merely observes on this subject : 
“* Pentastomata, androgyna, vasis nutritiis Trematodum more divisis instructa,”’ &c. ; 
but in the ‘ Historia Naturalis Entozoorum’’, he gives the following description : 
** Mediam corporis partem ovaria ferruginea replent, infra poros inferiores, (duas cir- 
citer lineas infra apicem anticum,) e glomere in sinistro abdominis latere, margini fere 
continuo, oriunda, tum in mediam corporis partem ad caudz fere apicem descendentia, 
in latiore vermis parte magis convoluta et coacervata, in parte tenuiore sensim simpli- 
ciora, ut in ultimo tandem apice decolora tantum conspiciantur ; ovaria ista si expli- 
carentur certe aliquot pedes longa forent, cute firmiore constant, nec facile disrampunt ; 
aperturam genitalem nullibi vidi, qua ovaria terminarentur, sed ipsa Polystomatis cutis 
facile rumpitur, ut illa prolabantur, et stato forsan tempore ova effundant. Heec ellip- 
tica, magna, flava et ovario aperto magno numero emittuntur, nunquam autem libera, 
sed tunica tenuissima candida laxa involuta sunt, qualem in nullo Entozoorum genere 
viderim. Prater ovaria, alia quoque vasa adsunt, candida (nutritia) tam superne in 
1 Syn. Ent., p. 584. 
» These are the fecundating organs, and communicate with the oviduct, not the intestine. 
3 tom. ii. pars 1. p. 442. 
