1897.] NEW SLUGS mOM BORNEO. 781 



an der Unterseite noch einen Eest A^on GevAinde. Der Liebespfeil 

 hat eine solide Kalkspitze. Der Penis ist ein diinner, in der 

 geraden Scheide mehrfach zusammengekriimmter Sclilauch, so dass 

 das innere Lumen dem ausseren Umt'ange durchaus unahnlich ist. 

 Eeceptaculum sitzend." 



After a careful perusal of the literature on these and allied 

 genera, and a comparison of Simroth's figures with the material 

 from Borneo, I fail to see where the line can be drawn between 

 Parmarion and Mkroparmarion. In both genera the shell is 

 variable. In the latter genus Simroth says the dart has a solid 

 calcareous point, whereas in the former he describes it as being 

 open at the end in the form of an oblique slit. In Parmarion 

 intermedium, the dart is solid, non-calcareous, and there is no opening 

 of any description. In Parmarion he describes the penis as being 

 long and straight, whereas in Mleroparmarion it is thinner and 

 constricted; but I would point out that mMicroparmarionpoUonerai, 

 Cllge. & Gr.-A.\ there is a long and straight penis. The value 

 of the sessile receptaculum seminis is lessened by the condition 

 which obtains in P. inipillaris, Humb., and more so by that in 

 P. intermedium. 



Trom the above facts it will be seen that the two genera, as 

 well as allied genera, are as yet but ill-defined, and that satisfactory 

 characters are yet wanting to define the precise limits of each 

 genus. I therefore sincerely hope that further material may be 

 forthcoming from Borneo and elsewhere whereby sound generic 

 characters may be established for these very interesting molluscs. 



EXPLANATION OP PLATE XLIV. 



Fig. L Parmarion everetti, n. sp. View from right side, X 2 (p. 778). 



2. Caudal mucous pore, X 3 (p. 778). 



3. Generative organs, x 3 (pp. 779, 780). 



4. Parts of tlie generative o'gans of Parmarion martensi, Simr. (after 



Simroth), (p. 779). 



5. Parmarion intermedium, n. sp. View from right side, x "5 (p. 779). 



6. Visceral mass, showing spiral fold, X 2 Cp. 779). 



7. Caudal mucous pore, X 3 (p. 779). 



8. Generative organs, X 2 (p. 780). 



9. Enlarged figure of Tjenis, showing ventral side (p. 780). 

 10. Dart, X 3 (p. 780)t 



IL Eeceptaculum seminis and duct, X 55 (p. 780). 



Lettering. 



alh.gl. Albumen gland. 

 d.s. Dart-sac. 

 h.d. Hermaphrodite duct. 

 h.gl. Hermaphrodite gland. 

 m. Muscles attached to vagina. 

 ov. Oviduct, 

 jp. Penis. 



pr. Prostate. 



r.m. Eetractor muscle. 



r.d. Eeceptacular duct. 



r.s. Eeceptaculimi seminis. 



V. Vestibule. 



v.d. Vas deferens. 



vg. Vagina. 



' Proc. Zool. Soc. 1895, pi. xiii. figs. 22-23. 

 Pboc. Zool. Soc— 1897, No. LI. 51 



