SPECIES OF PLANARIAN WORM. 39 
(2. p. 48) that the height of the “ Driisenkanten-epithel ” is less 
than that of the dorsal epithelium, while I find (g/.ep) that it 
greatly exceeds that in height. Another interesting fact worth 
noting is that Rh. Howesi is the only member of the genus 
Rhynchodemus in which these peculiar marginal glands occur. 
The cilia so well seen towards the middle of the underside do 
not extend to this glandular area. 
All Land-planarians are hermaphrodite, a pair of ovaries being 
situated near the anterior end of the body. These give rise to an 
oviduct on each side of the body (cf: text-figs., ov.), which generally 
unite before opening posteriorly into the genital atrium. The 
testes lie farther back than the ovaries, and the two vasa defer- 
entia (v.d.), carrying the spermatozoa, open as a rule separately 
into the vesicula seminalis (v.s.), from which a duct leads into the 
genital atrium. The genital opening is always situated behind 
the mouth. In R. Howesi it is only very faintly indicated by a 
minute white spot (PI. 6. fig. 2,7) on the underside of the body, 
13 millim. behind the oral aperture. 
Fig. 2.— Rhynchodemus Howesi.—Longitudinal section through reproductive 
organs (somewhat diagrammatic). 50. 
ut, uterus; /.0v., left oviduct; 7.0v., right oviduct ; va, vagina; gl, glands ; 
p, penis, v.s., vesicula seminalis; g, genital pore; gl.c., glandular canal 
sp, spermatozoa ; 7p, duct from vesicula seminalis; 7.vd., right vas deferens ; 
l.ud., left vas deferens. 
Instead of giving.an accurate drawing of a longitudinal 
section of the reproductive organs, it seemed to me preferable tio 
show the disposition of the various parts in Rh. Howesi by means 
of a somewhat diagrammativ sketch (text-fig. 2). The repro- 
ductive organs in this species agree in the main points with those 
of R. terrestris and R. Scharff, but they are more nearly related 
