516 Mr. C. R. Narayana Rao on the Anatomy of 



and 10/11. Each aperture is a large transverse slit with 

 tumid lips. 



The female pores in 11/12 internal to seta-line a, con- 

 spicuous only in a few forms. 



Colour. — Live specimens are bright deep green or almost 

 bhie, the clitellum being distinguished by crimsou-red. The 

 ventral median line is grey, almost transparent, through 

 which the nerve-cord is visible. The red of the clitellum 

 fades in the preserving fluids, and the warm blue degenerates 

 into a dull olive-green. 



Internal Anatomy. — The skin of this species of Draivida 

 is structurally more complex than that of any other worm 

 with which I am acquainted. When a few drops of formalin 

 were added to the water in which the worms were plunged, 

 they became coated all along the dorsal line with a dense 

 milk white secretion in large drops. Being somewhat 

 viscous, it dissolves in water with difficulty and hot water 

 coagulates it. Obviously it is rich in albuminous contents and 

 has a slight alkaline reaction ; when dried it forms minute 

 cubic crystals. This phenomenon, not noticeable in any of 

 the other species in my collection, led to a microscopic exam- 

 ination of the sections of skin (PI. XVII. fig.9). It comprises 

 the usual layers of polyhedral epidermal cells ; the chromato- 

 phnres form a fairly tliick layer below. I do not find any 

 difference as regards the structure between the chromocytes 

 bearing the green pigment on the body and those bearing 

 the I'ed on the clitellum. In addition to the ampulliform 

 mucous cells situated between the polyhedral epidermal 

 cells, there occuis another type of glands composed of 

 syncytial aggregation of a large number of cells. There are 

 a pair of such glands in each somite, placed at right angles 

 to the axis of the body on the dorsal surface. The border 

 of the gland is sinuous, indicating the incomplete fusion of 

 the cells, whose boundaries are not, however, recognisable 

 in the body of the structure. The spaces seen in the body of 

 the gland constitute the duct, wdiich is intracellular, and the 

 external orifice is placed close to the dorsal pore on either 

 side. Microscopically examined, the secretion shows the 

 ]n'esence of coelomic corpuscles, which must have been added 

 to it outside the body. Many species of Megascolex, Acan- 

 thodrilus, and Octodiates are known to extrude quantities of 

 coelomic fluid under irritation besides the ordinary mucus, 

 but a specific secretion of this nature is remarkable in a 

 worm not distinguished much by size. 



Muscular System. — Around the seta-follicles in the an- 

 terior somites the skin is disposed in discoidal form with 



