cal expansions present. No spicules nor gu- 
bernaculum. Pre-anal fusiform sucker without 
chitinous rim, but a border of delicate cuticu- 
lar membrane at the anterior and posterior 
limits, as ifthe sucker had two cuticular mem- 
branes. Vulva at the junction of the anterior 
and middle thirds of body. 
Habitat: intestine and caecum of Mam. 
mals (Rodents). 
Type-species one: Only known and He- 
teroxynema cucullatum Hall, 1916. 
Habitat: large intestine and caecum of 
Eutamias amoenus operarius. 
Geographical distribuition: Sant’Acacio, 
Costilla Country Colorado. 
Heteroxynema cucullatum Hall, 1916. 
Dimensions: 
g Length: 2.786 to 4,47 mm.; width: 
0,49 t, 0,170. 
2 Length: 7,36to 7,9 mm.; width: 0,345 
to 0,415. 
Cuticle transversally striated. Lips three, 
simple, one dorsal and two latero-ventral ones, 
each with a medium papilla, apparently dou- 
ble and separated by a papilla from the ad- 
jacent lips. Buccal capsule simple and shal- 
low. Oesophagus club-shaped, thickening gra- 
dually towards the posterior extremity and 
ending in a bulb, which is sometimes deep- 
set in the anterior dilated extremity of intes- 
tine. Cervical alae prominent, beginning at 
the base of lips and winding towards the 
ventral surface. 
Male: Diameter of heád about 0,065 mm. 
Oesophagus without bulb, 0,355 0,515 mm. 
long and 0,050 to 0,070 mm. wide. Bulb 0,136 
mm. to 0,162 mm. long and 0,112—0,145 mm 
thick. Nerve collar 0,130 mm. from cephalic 
extremity. Caudal expansions weakly deve- 
loped. The greater part of the genital papil- 
lae are grouped round the cloaca; one pair 
isolated, 0,085—0,112 mm. from posterior ex- 
tremity. Genital opening 0,235 mm. from ex- 
tremity. Six ad-anal papillae: two larger ex- 
ternal ones and two lesser exactly median 
ones at each side of these. Just behind these 
papillae is a sub-median pair followed by a 
49 
single papilla on the middle line. No pre-anal 
papillae were observed, the total number be- 
ing eleven. No spicules. Sucker fusiform, ha- 
ving on the lateral margins two cuticular, fe- 
nestrated membranes apparently interrupted 
in the middle tine at the anterior and poste- 
rior extremities; length of sucker: 0,112— 
0,130 mm.; width: varies on acount of the 
contraction and distension of the flexible bor- 
ders, the posterior limit is 0,515—0,600 mm. 
from tail end. 
Female: Posterior extremity sharp-point- 
ed. Oesophagus without bulb, 0,430 — 0,535 
mm. long, and 0,056 0,070 mm. thick. Bulb 
0,198—0,240 mm. long, 0,130-0,185 mm. 
wide. Nerve collar 0,170 mm. from cephalic 
extremity. Anus 1,65 mm. from caudal extre- 
mity. Vulva at the junction of the anterior 
and middle thirds of body, 1,80- 3,265 mm. 
from head. Ovijector with spirally curved 
walls, initial part turned from the vulva 
towards the cephalic extremity followed by a 
tail. Uterus apparently double; uterine ho- 
oklets occupy'the posterior part of body. Eggs 
long, with depression on one of the sides, 
obtuse extremity; 0,098—0,100 mm. long and 
0,035 mm. wide. 
Habitat: great intestine and caecum of 
Eutamias amoenus operarius. 
Geographical distribution: Sant Acacio, 
Costilla County, Colorado. 
Material-type, Number 16637 in Bureau of 
Animal Industry, U. S. A. Helminthological 
Collection. 
Genus NUMIDICA Barreto, 1918. 
Synonymy. 
Allodapa SEURAT, 1915 pr. parte. —p. 
122 text-figs. 1 to 4. 
Historical notice 
In the “Comptes rendus des Séances de 
la Société de Biologie”, in 1915, SEURAT 
describes a nematode living in the caecum of 
the Algerian fox (Vulpes (V) var. arlantica 
WAGNER), under the name of Allodapa nu- 
midica. 
