318 ON THE POLYCLADS OF THE “‘ SKEAT EXPEDITION.” [ Apr. 21, 
species described above, but, judging from Collingwood’s figure, 
in the arrangement of the eye-spots it is sufficiently distinct. 
Lnterature. 
1. Bercenpat, “ Kongl. Fysiogr. Sallskapet,” Lund Handlingar, 
Ny Foljd, 1892-93, Bd. 4. 
2. CoLyinewoop. ‘Trans. Linn. Soc. Lond. ser. 2, Zool. i. 1875, 
p. 83, pls. 17-19. 
3. GRAFF, von. Zeitschr. wiss. Zool. lv. 1893, p. 189. 
4. Larpnaw. Fauna and Flora of the Maldives and Laccadives, 
ilo [Dy Pars JOS Kaen YE 
5 Mem. & Proc. Lit. & Phil. Soc. Manchester, xlvii. p. 1 
(1903). 
6. Lane. Naples Monogr. xi., 1884. 
7, PLEHN, von. Jena. Zeitschr. xxx. p. 137, t. vili. & xiii. 
8 
) 
Ergebn. Plankt.-Exp., Heft 1., 1896. 
Semon’s Zoologische Forschungsreisen, Bd. v. pp. 329- 
304, t. XXlil. 
Abh. Senckenb. Gesell. xxiv. 11. pp. 145-146 (1897). 
It —— Jena, Zertschr. xxxi. p. 90; t. v. (1898): 
Zool. Jahrb. Syst. xii. pp. 448-452 (1899). 
13. Srummur-TRAUNFELS, von. Zeitschr. wiss. Zool. lx. p. 688, 
t. XXXV.—XXXVII1. 
14. Verritt. Trans. Connect. Acad. vill. p. 459, pl. xliv. 
a a 1x, pl O23. 
16. WoopwortTH. Bull. Mus. Comp. Anat. xxxii. 4, pp. 63-67, 
pl. i. (1897). 
EXPLANATION OF PLATE XXIII. 
Fig. 1. Spine from the lumen of the penis of Planocera sp., p. 302. 
2. Section passing through the penis and prostate organ of Notoplana evansii, 
. 302. 
3. Teaneverss section through the penis of Leptoplana malayana, p. 306. 
4. ‘Transverse section through the penis and prostate gland (?) of Bergendalia 
anomala, p. 310. 
5. Section through the rudimentary organ of penis-like structure of the same 
species, p. 311. 
6. Section through the spiral part of the vagina of the same, p. 312. 
7. Section across the antrum masculinum of Asthenoceros woodworthi, p. 315. 
These organs are directed obliquely forward, and consequently both appear in 
some of the sections. The granular appearance of the prostate in this region 
is rather exaggerated in the figure, but it becomes more marked towards its 
extremity. 
8. Bergendalia anomala, p. 306. 
9. Pseudoceros bedfordi, fragment of anterior part of body, p. 314. 
10. Pseudoceros ? rubellus, p. 314. 
Explanation of Lettering of Plate and Text-figures. 
a.m., antrum masculinum. pr.e., chamber of the prostate. 
a.m.l., muscular walls of antrum mascu- pro., prostate. 
linum. ppr., prostate-like organ. 
d.e., ductus ejaculatorius. S., Septum between chamber of 
d.pr., prostate duct. prostate. 
ep., epidermis. st., stylet of penis. 
m.pr., muscular walls of prostate. | t., tentacles. 
m.v., muscular sheath of vagina. va., lumen of vagina. 
p., penis. |  v.d., vasa deterentia. 
pp., vestigial penis ? v.8., vesicula seminalis. 
pr., prostatic cells. 
