352 DR. T. S. COBBOLD, FURTHER OBSERVATIONS ON ENTOZOA. 
only ten months old, I introduced nine living Pentastomes, and in the second — an old dog 
five examples. All the worms quickly disappeared, and I therefore fully expected a 
satisfactory result. I was doomed to disappointment. On the 4th of March the young 
animal was destroyed, and I made a most careful dissection of the head, without, how- 
ever, finding a single Pentastome in any of the nasal, frontal or facial cavities. I regret 
to add, that the old dog was subsequently killed and thrown away during my absence, 
and I have not since had an opportunity of repeating the experiment. Prof. Leuckart, 
having seen the memorandum above-mentioned, suggests that the parasites may have 
been dislodged by the dog's sneezing. 
3. Trichocephaltts afitnis, Rudolphi. 
T. affinis, Rudolphi ; Miram ; Lamarck ; Gurlt ; Mayer ; Dujardin ; Diesing, Helminth, vol. ii. p. 296 ; 
Kuchenmeister, Parasiten, p. 275. 
T. Cameli, Rudolphi. 
T. ovis, Abildgaard. 
T. Giraffa, Clot-Bey (non descript), in Bulletin Scient. de PAcad. Imp. de St. Petersb. 1839, torn. vi. 
p. 94; also in Isis, 1839, p. 663 ; Diesing, Syst. Helminth, vol. ii. p. 294 (species inquirendse) . 
T. gracilis, Cobbold, Proceed. Zool. Soc. for 1860, p. 103 (non descript.). 
Remarks. — In a paper, entitled " Contributions to the Anatomy of the Giraffe," which 
I had the honour of communicating to the Zoological Society on the 14th of February 
last, the circumstance of my having detected Trichocephali in the caecum and colon of that 
ruminant is already mentioned. At the time referred to, I purposely abstained from 
giving any particular account of the worm, but, believing it to be a distinct form, I 
recognized it provisionally under the title of T. gracilis. Subsequently, finding the 
latter title to be applicable to a Trichocephaliis discovered by Olfers and Natterer in two 
species of Agouti, I abandoned it ; and I have, moreover, since satisfied myself by a very 
careful investigation, that the species in question is identical with the T. affinis of Eu- 
dolphi. Under the synonym of Trichocephalus Giraffa, Diesing has grouped this worm 
among his doubtful forms, its presence having been previously noticed by Clot-Bey in 
the small intestines of a giraffe dissected at Cairo in the year 1839. 
Viewed with the naked eye (fig. 7), one can scarcely detect any difference between this 
form and the well-known T. dispar of the human subject— an observation which applies 
to some other species of the same genus. In my examples the females measure from 
lf~2 inches in length, over all ; the males reaching from 2-2| inches. With the pocket 
lens, the surface of the worm appears smooth throughout, but when highly magnified, 
peculiar markings are seen on the anterior thin portion, which probably also extend over 
the body proper. The so-called neck presents a tolerably uniform thickness along its 
entire course ; it is so narrow as to measure only from T25-T2 oth of an inch transversely, 
whilst the finely-pointed head itself, immediately below the mouth, has a diameter less 
than ToVo tn of an inch. In the fresh state the head appeared to be lobed, or rather, 
I may say, furnished with two alseform lobed appendages, as represented in fig. 8 ; but in 
preserved specimens these appearances either partially or entirely disappear, leaving one 
m doubt as to their true nature. Kuchenmeister has noticed the evanescence of appa- 
