Brackish- water Polyclads. 
189 
cluster on either side of the median Hne, as shown in the accompanying figure. In 
addition there are present small marginal eye-spots in a large number, arranged 
partly in a row and partly in crowded rows. They do not extend completely round 
the body, but cease altogether to exist at about the hind border of the anterior third 
of body. 
Body-wall. — The epidermis contains a large number of rhabdites, less numerously 
in that of the ventral than of the dorsal side. The basement membrane is very thin, 
and the muscles of the body-wall is but feebly developed. 
Digestive System. — The mouth opens into the centre of the pharynx, which is 
somewhat less than one-third the length of body and is placed somewhat in front of 
the middle of the body. The pharyngeal wall is moderately folded. The main gut 
is long, rather narrow, and possesses numerous pairs of lateral intestinal branches 
2. 
Text-fig. 2. — Eye-spots, tentacular, cerebral and marginal, of SAt^Z/or^/m awrtm. x 25. 
the subbranches of which nowhere undergo anastomosis. In the intestinal wall there 
exist as usual a large number of Minot's glands, but the homogeneous spherules 
observed in the preceding species are not present. 
Male Genital Organs.^Th^ following description of the genital end-organs may 
not be quite accurate, since the specimen was unfortunately in a state unfit for 
close study. 
The testes are ventrally distributed, chiefly in the middle parts of body. The 
end parts of the seminal canal of both sides expand into the accessory seminal 
vesicle, the connection of which with the ejaculatory duct could not be exactly de- 
termined. The ejaculatory duct, after undergoing much convolution far in front of 
the penis, pursues a backward course, finally to open at the tip of penis. The penis 
is a very small, bluntly conical body, projecting into the antrum musculinum. The 
male aperture is placed near the posterior end of the body. A certain part of the 
