II. A FAUNA WITHIN ANIMALS. 41 



CHAPTEE II. 



A FAUNA WITHIN ANIMALS; BEING DESCRIPTIONS OF NEMATOID ENTOZOA FOUND 

 ASSOCIATED WITH ENTOPHYTA, AND OF OTHEES ALLIED TO THEM. 



Associated with the extraordinary flora of the intestinal canal of Julus margina- 

 tus and Passalus cornutus, there is also a rich fauna. Within the former animal, 

 there exist, with a good deal of constancy, the following entozoa : — 



1, Qregarina Juli marginati,^ within the proventriculus ; 2, Ascaris infeda; 3, 

 Streptostomum agile; 4, Thelastomum attenuatum ; 5, Nydotlierus velox -^ 6, Bodo 

 julidisf' and 7, a species of Vibrio, within the ventriculus and large intestine. 



In Passalus cornutus are found : — 



1, Qregarina Passali cornuti,* within the proventriculus ; 2, Hystrignathus rigidus, 

 within the ventriculus. 



External to the intestinal canal, and within the abdominal cavity, there is like- 

 wise found an enormous quantity of a species of nematoid worm, apparently not 

 fully developed,* and in the thoracic cavity a second species is occasionally observed.^ 



The only helminth observed in the intestinal canal of Jidus pusillus was a spe- 

 cies of Qregarina.'' 



The common cockroach, Blatta orientalis, contains within its intestinal canal 

 several species of animals, frequently in great numbers, and also, according to 

 Valentin,^ an entophyte which grows from the mucous membrane of the large in- 

 testine. The same plant, Valentin states, grows within the rectum of Astacus 

 fluviatilis. He refers it to the genus Hygrocrocis, under the specific name of II. in- 

 testinalis, and thus characterizes it : " Fila simplicia, t'enuissima, prolonga, articulata, 

 serpentina, apice recta, moniliformia, articulis gldbosis." 



A plant agreeing with this description I have not been able to find in the same 

 insect, the cockroach, introduced into this country ; but, instead of it, in the same 

 situation mixed with the contents of the intestine> or growing from its mucous 

 membrane, or occasionally from the nematoidea infesting the cavity, simple, 

 inarticulate, amorphous filaments from the ^-^^-q-q to the 2 q^^-q o of an inch in dia- 

 meter (PL VII. 7, e). 



The entozoa of Blatta orientalis are : 1, Vibrio; 2, Bodo; 3, Nyctotherus ovalis ;^ 

 4, Qregarina;^" 5, Streptostomum gradle; and 6, Thelastomum appendiculatum. 



' Trans. Am. Phil. Soc, x. 237. " lb. x. 244. '^ lb. * lb. x. 238. ' lb. x. 241. « lb. 243. ? lb. 238. 

 * Repert. fur Anat. mid Phys., Band 1, S. 110, 1836. Robin : Des Viget. qui crois. sur L' Homme, 

 etc., p. 82, 1847. " Trans. Am. Phil. Soc, x. 244. «> lb. x. 239. 



