A NEW SPECIES OF MONIIJGASTEE FROM INDIA. 381 



Fig, 2.— One of the clisetae. 



Fig. 3. — A dissection of the left half of the animal, to illustrate the 

 arrangement of the genital organs, and the position of the gizzards and the 

 oblique muscles. Enlarged about 10 times. The somites are numbered, as 

 also are some of the septa. Note the shifting of Septum x/xi. cop. sac. 

 Bilobed copulatory sac, through which the spermathecal duct opens to ex- 

 terior (see Fig. 5). ann. band. Annular bauds between the gizzards, giz. 1, 

 2, 3, 4. The four gizzards, obi. m. Clique muscles (see Fig. 6) in certain of 

 the somites, o. ch. Groove, due to interruption in longitudinal muscles 

 throughout the body, along the line of the outer chsetse (a similar groove 

 exists in connection with the inner chaetse). oss. (Esophagus, ovd. Funnel of 

 oviduct, sp. d. Sperm-duct. sp. sac. Sperm-sac, lying in a pouch formed by 

 Septum ix/x. spth. Spermatheca. 



Fig. 4. — Yiew of male organs on a smaller scale. The pouch of Septum 

 ix/x is removed, and the sperm -sac {sp. sac) turned forwards, showing the 

 greatly convoluted sperm-duct {sp. d.) lying in Somite ix. The spermiducal 

 funnel is seen by transparency through the thin wall of the sperm-sac. obi. m. 

 Oblique muscles attached to prostate, the duct of which is now seen. o. ch. 

 The groove in line of outer chaetae. 



Fig. 5. — A semi-diagrammatic longitudinal section through the genital 

 somites. It is diagrammatic in so far as it shows both spermathecal pore 

 and atriopore, the entire ovary, and other features which really exist in 

 neighbouring sections. The external rings are labelled with Roman numerals, 

 the cavities of the somites with Arabic numerals ; the septa are lettered. 

 at. 0. Male pore, or atriopore. circ. Circular muscles of the body-wall. 

 cop. sac. Copulatory sac, showing entrance of spermathecal duct. Ig. m. 

 Longitudinal muscles of the body-wall. neph. Portions of nephridial tube. 

 neph. bl. Csecal bladder of nephridium. obi. nms. Oblique muscles cut across. 

 sp. d. 0. Aperture of sperm-duct into atrial cavity; its course is shown from 

 the septum, backwards in the longitudinal muscles of body-wall, and through 

 the prostate, sp. funnel. Funnel of sperm-duct, which does not actually 

 occur in the same section as the testis, spoa. Spermatozoa in sperm-sac ; 

 some are seen attached to funnel, spth. Spermatheca. spth. d. Spermathecal 

 duct. spth. 0. Aperture of spermatheca. 



Fig. 6. — Diagrammatic transverse section through half the body in 

 anterior region, to show position of oblique muscles, i. ch. Groove, along 

 which are inserted the inner chsetse. o. ch. Similar groove for outer chsetse. 

 n. c. Nerve-cord. sub. n. v. Subneural vessel. 



Tig. 7.— Half a transverse section through the intestinal region, in order 

 to show the peculiar band of longitudinal muscle {v. long, mus.) which 

 traverses this region of the body. The lateral thickening of the body-wall is 

 also seen in these two sections. 



