10 DR.T. S. COBBOLD ON A NEW ENTOZOON. (Jan. 13, 
round worms in large numbers in the general serous cavity of the 
abdomen. Moreover there had to be taken into consideration the 
peculiarities of the digitigrade mammal thus infested, its compara- 
tive rarity, and also its limited area of geographical distribution, 
these several influences being unquestionably concerned in the ‘‘ fixa- 
tion,” so to speak, of the specific form likely to be encountered. It 
is not surprising therefore that our anticipations in the above rela- 
tion should have been more or less completely verified; and ac- 
cordingly it turns out that we here encounter a new genus of inter- 
nal parasites offering peculiarities of structure, and apparently also 
of habit, which on the whole suggest a slight approximation to the 
ordinary filarine genera, on the one hand, but with a closer con- 
nexion with the remarkable genus Dracunculus on the other. When 
all the facts bearing upon the genetic relations of the Guinea-worm 
come to be fully known, it may then turn out that my determina- 
tions, in respect of the affinities of the new worm, are somewhat wide 
of the mark; but, in the meantime, the following data will show 
the grounds on which I have provisionally asserted this alliance. 
All the specimens received by me, thirty-four in number, were 
females ; therefore, in the absence of any knowledge of the corre- 
sponding male parasites, the following characters must be regarded 
as applicable only to one of the sexes :— 
Order NEMATODA, Rud. 
Suborder Nem. Proctrvucaa, Dies. 
Family Firarrpea, Dies. 
Subfamily CaErLonemrp14, Dies. 
ACANTHOCHEILONEMA, g. n. 
Head furnished with three spinous lips; body filiform ; female 
endoparasitic in mammals. 
A. DRACUNCULOIDES, sp. n. 
Body smooth, finely attenuated in front, uniformly thick below ; 
head sharply pointed when the lips are closed, obtuse when exserted ; 
neck spirally twisted in four or five circles ; tail abruptly truncate, 
with a solitary, central, very slightly projecting lobe; no reproduc- 
tive orifice visible. 
Length 13" to 23"; general breadth 1,” to J”. 
This combined generic and specific description, though sufficient 
for future identifications, may, I think, be profitably supplemented 
by other particulars relating to size, external form, and general 
organization, amongst. which I have remarked the following :—The 
head immediately beneath the insertion of the lips measures so little 
as the ;,/,,” in diameter, whilst the neck proper gives only twice 
the same amount of thickness. The tail is fully 3,” in breadth, its 
feebly pronounced central lobe being no more than the 54," wide at 
the base. The mature eggs, or those containing more or less per- 

