612 
differences. As has been mentioned the moulting “% are smaller 
than the 2©. The very marked differences present in the posterior 
part of the body of dd and $2, also occur in the moulting {d' and 
22. In both the cuticular tail-point is thrown off together with the 
old cuticle. In preparations of the moulting °, we see the long tail, 
somewhat rounded at its extremity, beneath the old cuticle; the 
distance between the anus and the extremity of the tail is rather 
considerable here. In the moulting ~ however, this distance is small and 
here the posterior part of the body shows already all phenomena 
described in detail by Raimumrr 1883, Eurers 1899, and Jerke 1900. 
Zoological laboratory of the Veterinary College. 
Utrecht, May 1920. 
LITERATURE CITED. 
Enters, H. 1899. Zur Kenntnis der Anatomie und Biologie von Oxyuris curvula 
Rud. Arch. f. Naturg. Jhrg. 65. Bd. 1. 
Jerke, M. 1900. Zur Kenntnis der Oxyuren des Pferdes. Jen. Zeitschr. der 
Naturw. Bd. 35. 
Martini, E. 1916. Die Anatomie von Oxyuris curvula. Zeitschr. f. wiss. Zool. 
Bd. 116. 
Ramet, A. 1883. Note sur le male de l'Oxyure du cheval. Bull. Soc. Zool. de 
France. T. 8. 
Ramuet, A. 1917. L'Oxyurose des Equidés. Receuil de Med. Vétér. T. 98. 
Ratturt, A. et Henry, A. 1903. Une forme larvaire de |’Oxyure du cheval. 
Archives de Parasitologie. T. 7. . 
Seurat, L. G. 1914. Sur l'évolution des Nematodes parasites. Je congrès int. 
de Zool. Monaco. 
ABBREVIATIONS. 
an. = anal opening. 
C.0. = + mouth-cavity. 
cut. = imaginal cuticle. 
l.cut. = larval cuticle. 
c.p. = larval cuticular point. 
ent. = intestine. 
Ke: = lateral cells. 
mm. = margin of mouth. 
musc. = muscles of the body-wall. 
ur. = rectal muscles. 
n. = nerve-ring. 
c.ph. = corpus pharyngis. 
t.ph. = isthmus pharyngis. 
b.ph. = bulbus pharyngis. 
c.ph.w. = wall of the corpus pharyngis. 
vr: = rectum. 
rz. = rectal glands, 
v. = valves of the bulbus pharyngis. 
