40 



CRITICAL REMARKS ON CERTAIN FORMS OF CHLORITIS, Wr I 

 DESCRIRTIONS OF TWELVE NEW SPECIES. 



By G. K. Gtjbe, F.Z.S. 



Read \1th January, 190t). 



PLATES IV AND V. 



Skveral species of Chhritis, bavins been insuffifienth' detiued, and 

 not properly compared with their allies, are at present little understood; 

 and, as a consequence, some confusion exists in collections containing 

 them. One or two, considered identical with previously described 

 species, have proved to be distinct ; while otbers, thought to be 

 distinct, bave been found, on closer examination, to be indistinguishable. 

 In applying myself to these matters, I have been enabled, owing to 

 the kindness of Miss Linter, Mr. J. H. Ponsonby, Mr. E. A. Smith, 

 and Messrs. Sowerby and Fulton, to study an extensive series of shells 

 of this genus ; and the collections thus examined, together with the 

 material in my own collection, liave been found to contain no less than 

 twelve new species. Finally, the kind co- operation of Mr. Smith has 

 enabled me to illustrate one of Pfeiffer's hitherto unfigured species. 



Chlouitis ungulina, L. 

 This, the earliest known species and the type of the genus, varies 

 considerably in colour, in the excavation of the spire, and in size. In 

 a series, placed at my disposal by Messrs. Sowerby and Fulton, the 

 colour ranges from dark chestnut and sienna brown to pale ochreous. 

 Typically, the spire is deeply immersed, each succeeding whorl 

 projecting above its predecessor, except the last quarter of the last 

 whorl, which is suddenly deflected in front and descends as far as the 

 periphery. In some specimens, however, the whorls ascend much 

 nioi'e slowly, and consequently the spire is much less immersed, the 

 third quarter of the last whorl being below the level of the penultimate 

 •whorl, and the upper half of the last whorl, near the aperture, less 

 sloping from the suture to the periphery, giving the shell a distinct 

 aspect from above ; two specimens, which possess the features indicated, 

 measure only 30 and 32 mm, in diameter respectively, and thus they 

 form a connecting link with 



Var. MINOR, Martens (not Fer.), 

 which is represented by two specimens from Amboina, measuring 

 27'5mm., one dark ochreous, the other blackish brown; the umbilicus 

 is here much less excavated, and the angulation becomes obsolete. 

 Two other specimens measure only 25 mm. 



Another specimen, which was submitted by Mr. Fulton in 1898 to 

 the late Professor von Martens, was accompanied by the following 

 remarks from the latter's own hand : '■'■ un(iulina, v. minor, of Ferussac, 

 Jieck, Pfeiffer, and myself, but I should have no objection today 



