106 MR. H. CHARLTON BASTIAN’S MONOGRAPH 
permanent tooth. It is not the whole of the rigid spear, however, that is renewed in 
this manner, but only what appears to be the anterior half of it. 
1. D. stasnauıs, Dujardin. (Plate IX. figs. 35-37.) 
Dujardin, Hist. des Helminthes, p. 231, pl. ui. fig. C. 
Female. Length 1", breadth 414". 
External Characters.—Body dark-coloured, tapering gradually anteriorly, but more 
abruptly posteriorly, where it terminates in a pointed filiform extremity. Head truncate; 
no papille. Integument thick, with longitudinal markings 5555 apart; lateral pores 
easily recognizable, and about 44553" apart. 
Spear zġy long. Œsophagus 3th of total length, posterior half enlarged. Intestinal 
cells having a tessellated arrangement, and containing dark-olive-coloured fat-particles, 
Posterior portion of intestine for about 35" narrower, and very scantily covered with 
cells and granules. Anus zz" from posterior extremity. Vulva slightly anterior to 
middle of body. Ova lying two or three abreast, within uterus. : 
Male. Length 1", breadth 114". 
(Esophagus proportionally longer than in the female. Anus 54,” from posterior ex- 
tremity. „Spicules solitary, 315" long. Oblique integumental striæ well-marked. 
Hab. Mud from freshwater ponds, Falmouth ; and New Cross, Kent. | 
Individuals of this species were found by Dujardin in the stomachs of the Carp 
(Cyprinus carpio) and of Gasterosteus levis; which specimens, he conjectures, had been 
swallowed accidentally by these voracious fish. | 
2. D. CanTERI, n. sp. (Plate IX. figs. 38-40.) 
Female. Length 77", breadth 415". 
External Characters.—Body tapering towards either extremity, especially posteriorly, 
where it is acuminated. Head truncate; no papille. Integument thick. 
Spear 35 long. (Esophagus about ith of total length. Hepatic or intestinal cells 
well marked. Anus 41." from posterior extremity. Vulva in the middle of body. 
Ova large. 
Male, same size as female. 
Esophagus longer. Spicules 31," long by 5000 broad. Oblique markings of integu- 
ment for some distance above spicules; also 8-11 minute suckers communicating with 
corresponding slanting channels through the integument, about 1,5" apart, in the mid- 
ventral region. 
Hab. Stagnant water, with decaying liverwort and moss : Falmouth. 
3. D. OBTUSICAUDATUS, n. sp. (Plate IX. figs. 41, 42.) 
Female. Length 3", breadth 44". 
External Characters.—Body tapering considerably for some distance from anterior 
extremity, but not at all posteriorly, where it is blunt and rounded. Head truncate, 
! Named after Mr. Carter. so as to connect his name with a i i | 
d species of that genus many of the details of whose 
anatomy were first carefully recorded by himself. E j 
