1872.] MR. G. F. ANGAS ON NEW LAND AND MARINE SHELLS. 611 



Diam. maj. 1 inch, min. 10 lines, alt. 10 lines. 



Hab. Ysabel Island, Solomon Group. 



This species has hitherto been erroneously regarded as the Helix 

 louisiadensis of Forbes ; but on referring to that author's description 

 and figures in the Appendix to the ' Voyage of the • Rattlesnake,' ' 

 I found it to differ so much as to induce me to examine the typical 

 specimens collected by the late Mr. J. M'Gillivray, and deposited by 

 him in the British Museum ; and on comparing the two species I 

 have no hesitation in pronouncing them to be totally distinct, setting 

 apart the wide difference of their localities. 



H. philomela may readily be distinguished from H. louisiadensis 

 by the absence of the rugose sculpture, by the outer margin of the 

 aperture being scarcely flexuous, by the presence of a conspicuous 

 callus on the columellar margin, and by the entirely different character 

 of painting, and the coloration of the apex, lip, and aperture. I 

 may observe that a shell from the Louisiade Islands, described and 

 figured by Dr. Cox, of Sydney, in these 'Proceedings' for 1871 (p. 

 323, pi. 34) under the name of Helix millicentce, appears to be iden- 

 tical with the H. louisiadensis of Forbes. 



3. Thalotia woodsiana, n. sp. (Plate XLII. figs. 4 & 5.) 



Shell convexly conical, solid, spirally ribbed, the ribs on the upper 

 whorls beaded, the beading becoming nearly obsolete "on the last 

 whorl, longitudinally obliquely striated, black, with irregular longi- 

 tudinal white markings ; spire convexly conical, apex acute, reddish ; 

 whorls 7|, slightly convex, the last whorl a little flattened at the base, 

 where the concentric ribs are stronger and more distant, and decussated 

 by radiating striae ; aperture subovate, somewhat contracted ; colu- 

 mella furnished with a few tubercles, and a prominent plait near the 

 base ; outer lip simple, thickened within, and furnished with tubercles 

 and several elongate denticles. 



Alt. 8, diam. 5 lines. 



Hab. Portland Bay, Australia. 



4. Thkacia alciope, n. sp. (Plate XLII. fig. 6.) 



Shell oblong-ovate, rather thin, whitish, nearly equilateral, coarsely 

 and irregularly concentrically striated ; anterior side ovate ; posterior 

 side truncate ; dorsal margin posteriorly slightly incurved, anteriorly 

 arcuate ; umbones small, subcentral ; umbonal ridge raised, obtusely 

 angulate, and slightly curved ; ventral margin arcuate ; hinge with 

 the cartilage processes small ; pallial sinus deep. 



Long. 1^ in., alt. 1 in., lat. 6 lines. 



Hab. Shark's Bay, Western Australia. 



5. Cytherea (Gomphina) moerchi, n. sp. (Plate XLII. 

 fig. 7.) 



Shell solid, transverse, triangularly ovate, moderately convex, equi- 

 lateral, faintly closely concentrically striated, white, with two indis- 

 tinct radiating bands of a few faint purple effuse blotches, and more 

 or less irregularly ornamented throughout with reddish purple lines, 



