560 
Journal of Agricultural Research 
Vol. XXX, No. 6 
0.30 by 0.36 mm. in one from Manila. 
The esophagus is from 0.66 to 0.89 mm. 
long and from 0.7 to 0.25 mm. wide at 
the point of greatest width (cardiac 
dilation). The bursa is nearly circular. 
On the ventral line there is a notch 
which is more or less completely closed 
by a small lobe. The supporting rays 
may be distinguished only under 
extremely favorable condition and the 
form of their terminations has not been 
made out. From examination of sev¬ 
eral specimens it is evident that there 
is^a complete set of rays; the dorsal, 
apparently undivided with the externo- 
dorsal rays are grouped closely 
together. The postero-lateral, medio- 
lateral, and externo-lateral rays form a 
compact group at the extremity of the 
transverse diameter. The ventro-ven- 
tral ray is close to the insertion of the 
ventral lobe, while the latero-ventral 
ray is just beside it. 
In two specimens, which after dis¬ 
section were in suitable condition for 
study, spicules were found. The small 
size of the spicules explains the failure 
of other observers to find them. 
They are similar in shape, about 25 y 
long, and lie just inside the cloacal 
opening. The opening itself appears to 
be supported by a chitinous ring, 
perhaps a modified gubernaculum. 
Except for the ring, no structure was 
seen that could be identified as a 
gubernaculum. 
Female. —The position of the vulva 
in respect to the total length of the 
worm is less variable toward maturity 
in this species than in S. trachealis. 
This is due to the fact that the uteri 
do not extend much farther behind 
the vulva than they do in front of it. 
Thus in gravid specimens the distortion 
due to the ripe eggs is nearly evenly 
balanced before and behind, and the 
ratio obtaining in mature but not 
gravid worms is maintained in the 
gravid specimens. In the specimens 
measured, the ratio of the distance 
between the anterior end and the 
vulva to the total length of the worm 
varies from 1:4.64 to 1:4.69. Owing 
to the anterior distribution of the uteri, 
the mature worms assume a distinctive 
tapering form, the posterior third 
being perceptibly thinner than the 
anterior two-thirds. 
A very young pair (female 3.58 
mm. in length) shows certain features 
of interest. The spicules are easily 
seen without dissection. The vagina 
is very short; the bifurcation of the 
uteri occurs within the area covered 
by the male bursa. The uteri make 
a short anterior loop and then proceed 
posteriorly to a point less than half 
the distance from the vulva to the 
tail. The ovaries occupy most of the 
space between this point and the 
posterior extremity. The vulva divides 
the total body length of the female as 
3 : 5 or 1 : 1. 66 
It appears that in this species the 
ovarian tissue degenerates after the 
eggs are discharged into the uteri, for 
in gravid specimens the ovaries are 
not perceptible. 
Host.—Bos taurus, doubtfully from 
Homo. 
Location. —Larynx. 
Geographic distribution. —Indo- Ma¬ 
layan region, Porto Rico, Brazil?. 
Travassos (1922) reports a case of 
S. laryngeus in man (Brazil). There 
is no evidence given to show whether 
he was dealing with this species or 
another. 
Syngamus dispar (Diesing) (pi. 1, 
fig. 5). 
Sclerostoma dispar Dies. 1851, Syst. Helm., 2: 
303; Dies., 1857, Denkschr. Akad. Wiss., 
Wien, Math.-naturw. cl., 13 (abt. 1): 16. 
Sygnamus dispar Molin., 1861, Mem. R. Inst. 
Veneto Sci., Litt. ed Arti 9:565. 
There is unfortunately no material of 
this species available nor is there a good 
or even a moderately good description 
extant. The available figures (Diesing) 
cover one or two important points not 
mentioned in the description. The fol¬ 
lowing is a summary of the specific 
characters, taken from all available 
sources: 
Mouth opening terminal; buccal 
capsule with ribs, presumably ending 
at the base in lancetlike teeth; bursa 
of male rather more strongly developed 
than in S. laryngeus; spicules probably 
minute (not described); vulva of female 
at about anterior fourth; coils of uterine 
complex reaching to posterior seventh 
of the total length; tail short, stoutly 
conical; anus just before tail. Length 
of male, 5-7 mm.; of female, 20-27 mm. 
Host.—Felis concolor. 
Location. —Trachea. 
Geographic distribution. —Brazil. 
Though little concerning this species 
is known, still it is highly probable that 
the species is valid. The only possible 
conflict is with S. kingi Leiper. A dis¬ 
cussion of the relationship is included 
under that species. 
Syngamus parvus n. sp. (pi. 1, fig. 1; 
pi. 2, fig. 15, 19). 
Similar in general shape to S. trachea 
but much smaller and with other male 
secondary sexual characters. 
Male. —About 2.4 mm. long, 0.22 
mm. in diameter, cylindrical, slightly 
