240 
papillae (see Fig. 1, a) all sessile; 6 pairs on 
ventrolateral surface posterior to ano-genital 
opening, 1 large, unpaired, immediately anterior 
to the ano-genital pore, 2 additional pairs 
anterior and lateral to this opening. No spicules 
observed either in free specimens or those in 
copulo. 
DISCUSSION 
At the time he recognized the genus Pseudo- 
physaloptera in 1934, Baylis described P.sori - 
cina from a species of Crocidura collected in 
the Tanganyika Territory, Africa, which, to the 
writers’ knowledge, is the only species that has 
been ascribed to the genus. 
P. soricina, however, has been recorded from 
other hosts by other investigators. In 1937 
Chen reported this organism from "Suncus 
coerulus” a shrew from South China. Baylis 
again recorded P. soricina in 1944 "from Suncus 
coeruleus kandianus” in Ceylon. Later Crusz 
(1946) described the worm from the musk 
shrew, " Suncus coeruleus ” in Ceylon. 
The first American finding of this helminth 
was made by Morgan (MS.), who reported 
it in the Masked Shrew, Sorex p. personatus, 
and in the Smoky Shrew, Sorex f. fumeus, in 
Tennessee, Kentucky, Wisconsin, and Iowa. A 
few females tentatively assigned as P. soricina 
by Morgan were also collected from the Short¬ 
tailed Shrew, Blarina brevicauda brevicauda. 
Specific differences in the genus Pseudophy- 
saloptera apparently are chiefly concerned with 
the male organism. The pattern of the caudal 
papillae on the ventral surface offers a basis for 
the separation of P. soricina and P. riukiuana. 
Baylis records four pairs of caudal papillae, 
all of which are typically sessile, post-anal, and 
lateral. Baylis has kindly sent one of us (D.L.) 
a pair of the cotype specimens for examination 
and comparison. We have confirmed four pairs 
of post-anal papillae (see Fig. 1, b), but be¬ 
lieve that there may be an additional lateral 
pair slightly anterior to the ano-genital open¬ 
ing. This pattern is in contradistinction to the 
six lateral post-anal pairs, the single, large 
PACIFIC SCIENCE, Vol. II, October, 1948 
ventromedian pre-anal, and the two lateral pre- 
anal pairs of papillae in the species at hand. 
The expanded cuticular collar at the anterior 
end of both sexes may be of significance. Baylis 
(1934) states, ’'The head (fig. 4) has the same 
structure as in Physaloptera, consisting of two 
hemispherical lateral lips, followed by a wider 
neck, the cuticle of which forms a collar.” At 
the same time, Baylis ( op. cit., fig. 4, page 347) 
shows little evidence of what the writers in¬ 
terpret as a "collar” although a relatively small 
proportion of the extreme anterior end is shown. 
Examination of a cotype female loaned by Dr. 
Baylis reveals no prominent inflation such as is 
present on P. riukiuana (see Fig. 1, e). 
There are other differences in body length, 
distance to nerve ring, and total length of 
esophagus that may be related to the degree of 
contraction of the worms at fixation. The forms 
under consideration here were generally well 
fixed and well relaxed. Both specimens loaned 
by Baylis were in a marked degree of contrac¬ 
tion. 
Chen (1937) and Crusz (1946) have both 
recorded P. soricina from shrews in China and 
Ceylon, but their descriptions seem to offer 
some doubt as to their specific identifications. 
The papilla pattern of the male in both in¬ 
stances is described as "numerous.” Crusz’s 
Figure 5 (page 63) shows at least a dozen 
large and small papillae in scattered and irre¬ 
gular distribution on each side over the ventral 
surface. The number and distribution of the 
caudal papillae of the male are markedly dif¬ 
ferent here from P. riukiuana. With reference 
to this point, in a personal communication 
under date of March 1, 1948, Baylis stated, "I 
have examined one of Mr. Crusz’s specimens ... 
I am not at all convinced that all the small 
papillae’ shown in his figures are really papillae 
at all. I think many of them are subcuticular 
structures 
As further evidence of a possible difference 
between P. soricina of Chen and Crusz and the 
present material, the absence of spicules might 
be cited. Chen (1937: 428) states, "Spicules 
