EXPLANATION OF PHATE Viilt 
N 
Fic. 1.—Reproductive organs of Nats variabilis, var. punjabensts, 
+) 
»> 
9) 
+) 
’ 
as seen in longitudinal section. The figure is diagram- 
matic, and in order to show all organs, is compiled from 
several successive sections. 
2.—Portion of clitellum of the same, as seen in surface view 
under oil-immersion lens. 
3.—Anterior part of body of Chetogaster orientalis, to show 
reproductive organs; clitellar area lightly shaded. The 
living animal represented as seen by transparency, 
obliquely from the ventral surface. 
4.—Middle region of the body of the same, showing an early 
stage in the development of the genital organs. Ovary 
and testis present, but not the spermathece; clitellum 
not developed. The organs of the other side were not 
seen. . 
At. = attfium ; cl.ep. = clitellar epithelium ; c.m, — citcular 
muscular layer; cy.—crop; /. = funnel of vas deferens; 
g.s. = genital sete ; /.m.—longitudinal muscular layer; 
o., ol. = ovaries; oes. = cesophagus; os. — ovisac; 
ova = ova; ph. = pharynx: pv. = prostate; s. —sete, 
sp., sp. = septa; sp. 4/5, sp. 5/6, sp. 6/7 = the septa 
between the segments thus indicated ; spth. = spermatheca ; 
spth!. = posterior extension of spermatheca into sperm- 
sac ; spz. = spermatozoa entering funnel of vas deferens ; 
spz'. = spermatozoa in body-cavity ; s.s. = sperm-sac ; st. = 
stomach; ¢.— testis: v.d. = vas deferens; y. = yolk of 
tipening ova; o = male aperture. 
5.—Anterior part of body of Dero sp.: d.s.o—d.s.3 = dorsal 
sete of fifth to eighth segments; g/.—= glands surrounding 
cesophagus ; tut. = intestine; m. = mouth; oe. — ceso- 
phagus; #2. = pharynx; pr. — prostomium; v.s.2 — v.s.8 
= ventral sete of second to eighth segments. 
6.—Lymph corpuscles in body-cavity: a and b, with large 
yellowish droplets; c, with white refractile particles. 
7.—Blood-vessels of hinder end of body of Dero sp.: al.= 
outline of ventral wall of alimentary canal; by. = branches 
of ventral vessel to intestine; d.v. = dorsal vessel; v.s. = 
ventral setal bundles; v.v. = ventral veggel. 
