Apr. 15,1925 
Ascaridia lineata , a Parasite of Chickens 
771 
to the forms just mentioned, there are 
several species of Ascaridia that have 
more than 10 pairs of papillae in the 
male. So far as concerns A. truncata 
of Travassos, Lane considers it con¬ 
generic with Gireterakis girardi, a 
new genus and new species having 
a bulbed oesophagus, described by 
himself, and he therefore concludes 
that A. truncata of Travassos is not 
i/iomm 
Fig. 18—Tail of female of Ascaridialineata (original) 
identical with Fusaria truncata of 
Zeder, the type species of the genus 
Ascaridia. Lane has assumed that 
the species described by Travassos as 
A. truncata possesses a bulbous oesoph¬ 
agus and therefore does not belong 
to the genus Ascaridia. In the writer’s 
opinion this assumption is unwarranted. 
In the absence of definite information 
to the contrary it seems fairer to 
assume that the species designated by 
Travassos as A. truncata has a simple 
oesophagus characteristic of the genus 
Ascaridia, a fact which is clearly im¬ 
plied in the generic diagnosis of 
Ascaridia as given by Travassos. Lane’s 
additional assumption that A. truncata 
of Travassos included more than one 
form must be left open to question 
in the absence of definite information 
on this point. The point to be con¬ 
sidered in this connection is that 
A. truncata of Travassos is a parasite 
of birds, whereas Gireterakis girardi is 
a mammalian parasite, the difference 
in host relationship of the two forms 
favoring the probability of their being 
different genera. 
One point on which Lane and Travas¬ 
sos agree, however, is the importance of 
the structure of the oesophagus in the 
classification of suckered roundworms. 
Lane (6), referring to the members of 
the genus Ascaridia, states that they 
will probably be subdivided in the 
future into several genera and will 
come to occupy the status of a sub¬ 
family at least, and that the genera 
Heterakis, Ganguleterakis, Gireterakis, 
and related forms having a bulbed 
oesophagus will constitute another sub¬ 
family. Future investigation may per¬ 
haps justify Lane’s position, but there 
appears to be no need at the present 
time to limit the definition of the genus 
Ascaridia beyond what is given by 
Railliet and Henry (11). 
SYSTEMATIC POSITION OF ASCA¬ 
RIDIA LINEATA 
In common with other species of the 
genus, Ascaridia lineata is generally re¬ 
ferred to the family Heterakidae, 
which is included in the superfamily 
Ascaroidea. According to Travassos 
(17 ), whose conception of the nematode 
superfamilies is to some extent at 
variance with that of Railliet and others, 
the genus Ascaridia belongs to the 
family Ascaridae, and not to the family 
Heterakidae, which he limits to forms 
having a bulbous oesophagus. Travas¬ 
sos furthermore assigns the family 
Heterakidae to the superfamily Oxy- 
uroidea, thus placing the genus As¬ 
caridia in a different superfamily, 
namely, Ascaroidea. This conception 
of the affinities of the genus Ascaridia 
differs radically from that of Railliet 
and Henry (11), who place Ascaridia 
with other suckered roundworms in the 
family Heterakidae. The genus As¬ 
caridia has undoubted affinities with 
certain Ascaridae so far as concerns the 
structure of the oesophagus and the 
presence of dentigerous ridges on the 
lips, but so far as concerns the presence 
of a preanal sucker and a bursalike 
tail in the male, it is closely related to 
the Heterakidae. 
The zoological position of the genus 
Ascaridia is a question that can not be 
finally settled until careful morpholog¬ 
ical comparisons are made not only of 
the adult forms, but also of the larvae 
at various stages of development, with 
those of corresponding stages of genera 
of Ascaridae on the one hand and with 
genera of Heterakidae on the other. 
