526 Mr. C. R. Narayan.i Rao on the Anatomy of 



markings in the line of genital pores. The male apertures 

 witli thick li[)S are large transverse slits in the furrow 10/11, 

 extending nearly over half aa and outwardly nearly over 

 half Z»c. The slit is straight, and the de[)ressioii surrounding 

 it is confined to the posterior half of somite 10. Tlie female 

 orifice is as large as the male opening, situated externally to 

 seta-line b. 



Each of the female pores extends inwards as far towards 

 the median line as the male orifices do. The lips are 

 swollen. The body-wall in the mid-ventral line between 

 the depressions surrounding the genital pores is raised in 

 the form of a ridge. Tlie spermathecal pores are large, slit- 

 like, curved openings iu line with the male pores, the chief 

 convexity being directed posteriorly. In front of each slit 

 is the already noticed glandular oval thickenings of the skin. 

 The nephridial pores are placed on seta-line cd. 



The colour of live specimens was distinguished by a grey 

 clitellum, the preclitellar portion was a mixture of yellow 

 and brown. The rest of the body was deep yellow with 

 blotches of brown. In the preserved specimen the yellow 

 is present only poorly. 



Internal Anatomy. — The skin is very tough and leathery, 

 and in point of histological structure is like the skin of the 

 foregoing species, D. elegans. 



Additional internal circular muscles in the genital somites 

 are present. 



Septa 5/6-8/9 are very thick ; the posterior face of septa 

 7/8 and 8/9 bear deep annular grooves with corresponding 

 ridges on the opposite surface. Septa 9/10 and 10/11 are 

 extremely tender or have atrophied. Subsequent ones are 

 excessively thin. 



There are two gizzards occupying somites 10-14. The 

 anterior is soft-walled, occupies 1^ segments^ and the 

 posterior is large, thick-walled, taking up 3| segments. 

 The alimentary appendages are few and fairly large. 



In regard to structure and disposition of vessels, the 

 circulatory system of this species is similar to those of 

 D. somavarpatana. 



The testicular sacs are very large, and, instead of depending 

 from the posterior face of septum 9/10, are attached to the 

 body-wall. This is the first example of Draivida in which 

 a sessile seminal vesicle is reported. Each vesicle has 

 convex outer surface, the anterior and posterior faces are 

 either bevelled or are hollow, and the inner margin, which is 

 a narrow ridge, is transversely ribbed. In cross-section it is 

 like the sector of a circle with the radii bent in. The length 



