NEW WORMS 
221 
References 
Maplestone, P. A. (1930). — Nematode parasites of pigs in Bengal. Rec. Indian Mus ., 32, 77-105. 
Tubangui, M. A. (1925). — Metazoan parasites of Philippine domestic animals. Philipp. J. Sci ., 28, 11-38. 
Proleptus malayi n. sp. from a dogfish. 
Four male and ten female nematodes belonging to the genus Proleptus Dujardin, 1845, 
were obtained from the small intestine of the spotted dogfish Scyllium sp. caught in Malayan 
waters. 
Baylis (1933) reviewed what was known of the various species which may be attributed 
to the genus Proleptus and concluded that six species could be recognised with some degree of 
probability. Since then three other species have been added to the fist. The specimens 
obtained off the Malayan coast differ from these and are here described as a new species. 
Description (Fig. 9) 
The Male: The male measures approximately 25 to 27.5 mm in length and 0.55 to 0.58 mm in maxi- 
mum thickness. The cuticular striations are at intervals of about 4.5. The anterior end is surrounded 
by a cuticular inflation. Each lip, in addition to the median lateral tooth, bears on its inner surface and 
projecting beyond its rim, two pairs of rather long spine-like teeth, situated subdorsally and subventrally 
and between these and the median tooth a few small denticles. There are three papillae on each lip. 
The anterior portion of the eosophagus is 0.6 to 0.62 mm long. The cervical papillae are immediately 
in front of the nerve ring which is 0.34 to 0.35 mm from the anterior end. The excretory pore opens at a 
distance of 0.5 to 0.67 from the anterior extremity. 
The caudal end of the male is spirally coiled, and the annulations, which are pronounced on the 
ventral surface, are serrated. The tail is 0.52 to 0.72 mm long and the caudal alae are well developed and 
symmetrical. There are eight pairs of caudal papillae and a single median papilla. The six anterior 
pairs, of which three are pre-anal in position, are long and rib-like. The median papilla is large and is 
situated immediately in front of the cloacal opening. 
The spicules are unequal and dissimilar. The right spicule is relatively stout and measures 0.185 
to 0.23 mm in length. The left spicule, which is provided with an ala, is more slender and measures 0.85 
to 0.9 mm in length. 
The Female: The female measures 40 to 42.5 mm in length and 0.8 r mm in maximum thickness. 
The anterior portion of the oesophagus is 0.73 to 0.93 mm long, the entire oesophagus being 5. 13 to 6.06 mm 
in length. The cervical papillae are situated at a distance of 0.33 to 0.35 mm from the anterior extremity 
and the nerve ring about 0.1mm behind the papillae. The excretory pore opens at a point 0.59 to 0.65 mm 
behind the anterior end. 
The tail of the female is bent somewhat dorsally and measures 0.42 to 0.489 mm in length. The tip ot 
the tail is bluntly rounded. The vulva is situated exceptionally far forward, at 13.6 to 14.34 mm from the 
posterior end. It opens on the posterior surface of a rounded prominence which appears muscular. The 
vagina runs posteriorly (anteriorly in two of the specimens). From the vulva and after a course of 1.13 
to 1. 14 mm gives off the two uterine branches which at first lie parallel to one another. The eggs are 
provided with thick shells (6 to 7^) and contain coiled larvae and measure 0.048 mm by 0.03 to 0.031 mm 
Discussion 
The worm described above is considered different from any of the known species. 
P. acutus Dujardin, 1845 differs considerably in size and length of spicules. The original 
description, which was based on a single male specimen, however, is too brief to allow further 
comparisons to be made. In P. obtusus Dujardin, 1845, the spicules are much longer. Besides, 
none of the four male specimens of the species described above shows the right angled bend of 
the tip of the right spicule described by Miller (1925) and considered by Baylis (1933) as “ a 
very characteristic feature of P. obtusus .” Although P. inflatus (v. Linstow, 1890) Baylis, 1933, 
is a larger worm, its left spicule is only about half the length of the corresponding spicule of 
the species described here. P. africanus (v. Linstow, 1899), Baylis, 1933 can be differentiated 
by the size of the spicules, tail length and size of the worm. P. robustus (v. Beneden, 1871), 
Seurat, 1916, can be distinguished by the length and appearance of the spicules, the number 
of caudal papillae in the male and the position of the vulvar opening. P. australis Baylis, 1933, 
MALAYA , No. 26 , 1953 
