0/1 neic Species of Marine MoUuscrt. 269 tlie eighth segment. Leps as in P. r'ormosensis. TT ings as in P./ormosensIs, except that the base and the costal cell, as well as tlie subcostal, are dark brown ; there is no pale spot beyond the stigma ; the ascending part of Cuj is dark-niargiued, and the cell Mj is shortly petiolate. EXrLA>:ATION OF PLATE XII. Fw. 1. Dicranomyia alticola, sp. n. Apex of 2 al A : men, side-Tiew (from oalsam preparation), x 35. Tiff. 2. Gnophomm'a similis, sp. n. Apex of $ abdomen, side-view (from dry specimen), x So. Fip. 3. Lininobt'a nitobei, sp. n. S hypopvginm from below, x 35. Fip. 4. Erioptera alboguttata, sp. n. <? hypopygium from below, x 35. Fig. 5. Tipiila rufomedia, sp. n. cf bvpi'^pytriiim from below, x 10. Fig. 6. Ditto. S rigbt clamper, inner side-view, x 23. Fig. 7. Ditto. Tip of $ abdomen from below, x 10. -Fi^. 8. Tipida rufizona, sp. n. Tip of $ abdomen from below, x 10. Fig. 9. Zongurio rubriceps, sp. n. (S hypopygium from above (penis removed), x 13. Fig. 10. Brithtira coniJfroHS, gen. et sp. n. Tip of cj abdomen, side-view (dry specimen). X O'o. Fig.W. Ditto. Apical half of wine, x 4. Fig. 12. Brithura cras^a, sp. n. Tip of S abdomen, side-view, x 5d. XXIX. — Descripiwns of Eight new Species of Marine Mouu.tca from the South Shetland Islands. Bv H. B. PkestoNj'F.Z.S. [Plate Xm.] The thanks of the anthor are due to Air. A. G. Bennett, of tile Falkhmd Islands, tor the material described in the present short paper ; when the difficulties of collecting in what is (even in the height of summer) an exceptionally rigorous climate, in great discomfort and without adequate apparatus, are taken into consideration, it will be readily appreciated how much Mr. Bennett was able to accomplish during his short stay at Deception Island in the summer of 1913-14. Limacina costulata. sp. n. (^Fig. 1.) Shell discoidal, almost planulate above, with slightly exserted apical whorls, extremely thin, white, vitreous, trans-parent ; whorls 4, the laj^t large and produced below, trans-ctrsely costulate : umbilicus deep, showing the coiling of the whorls ; aperture broadly auriform.