842 MR. A. GARRETT ON POLYNESIAN MITRIDiE. [NOV. 19, 



30. MlTRA FRATERCULA, n. Sp. 



Shell oblong, subfusiform, solid, shining, contracted at the base ; 

 spire moderately elevated, acute, brownish-yellow, transversely line- 

 ated with deep brown, and adorned with a spiral white band ; 

 whorls 8-9, plano-convex, slightly shouldered, longitudinally ribbed, 

 ribs small, closely set, angular, 16 to 18 in number, slightly 

 nodulose above, and the interstices remotely transversely impressedly 

 striated ; body-whorl large, roundly convex, granulated towards the 

 base ; aperture narrow, little less than half the length of the shell, 

 bluish white and lyrate within ; columella with four folds. 



Length 1 9 mill., diam. 8 mill. 



Hab. Tahiti, Rarotonga, Samoa, and Viti Islands {coll. Garrett). 



The animal is light brown, dotted and mottled with yellowish 

 white. 



A very rare species, found under stones on reefs, and belongs to 

 the same group as the preceding. 



31. MlTRA IAJTEO-FUSCA, n. Sp. 



Shell oblong-ovate, subfusiform, solid, smooth, polished, shining, 

 yellowish brown, with large whitish spots ; spire moderate, acute, 

 half the length of the shell ; whorls 9, convex, the upper ones 

 cancellated with fine longitudinal ribs and transverse impressed 

 lines ; body-whorl slightly ventricose, rapidly tapering, and obliquely 

 striated at the base ; aperture oblong, bluish white and lyrate 

 within ; outer lip thickened above ; columella with five strong folds. 



Length 16 mill., diam. 6| mill. 



Hab. Rarotonga, Cook's Islands {coll. Garrett). 



A very rare species, of which we obtained two examples from the 

 reefs. 



32. Mitra ExauisiTA, n. sp. 



Shell small, oblong, subfusiform, glassy, hyaline, pinkish red, 

 with two transverse brown lines enclosing a white band, the band 

 and one line continued up the spire ; spire ratber short, turreted, 

 subacute, little more than half the length of the shell ; whorls 9 

 (3 of which are embryonal), plano-convex, shouldered above, the 

 last rounded, much contracted aud granulated at the base, which is 

 produced in a short slightly twisted canal ; longitudinally ribbed, 

 ribs closely set, rather large, angular, slightly nodulose above, 12 to 

 13 in number, interstices transversely impressedly striated; aperture 

 narrow ; outer lip rather thin, notched above, and slightly sinuous ; 

 columella with four folds. 



Length 5 mill., diam. 3| mill. 



Hab. Paumotu, Tahiti, Cook's, Samoa, and Viti Islands {coll. 

 Garrett). It belongs to the same group as M. recurva and mirifica. 

 Notwithstanding its wide range, it is a rare species. Under stones 

 on reefs. 



32. MlTRA ZEBRINA, 11. S. 



Shell oblong-ovate, subfusiform, solid, ventricose, attenuated at 



