712 EET. R. BOOft M'ATSON ON THE 



scalar. Apex bluntly mammillated by the somewhat shapeless, 

 round, largish, glassy, ruddy, embryonic whorl. Whorls 4|, of 

 rather rapid increase. Suture rather faint. Mouth oblique, 

 roundish, being slightly peaked above and a little angulated ou 

 the pillar. Outer lip sharp but not thin, brilliantly iridescent 

 within. Inner lip very much thickened by a pearly pad, which is 

 very thick below where it envelopes wbat might otherwise have 

 been a tooth on the point of the pillar. The pad is thinner in the 

 middle of the pillar, and thickens again at the junction with the 

 body-whorl, where it thins out quickly. The lip here is very 

 slightly reflected on the umbilicus. Umbilicus very small and 

 contracted, not so much by the reflection of the inner lip as by 

 the pillar being bent round to the right across it. Operculum 

 very thin, yellow, horny, with about eleven very faintly defined 

 turns. H. 0-28 in. B. 0-37, least 0-26. Penultimate whorl 

 0-08. Mouth, height 0-2, breadth 0-2. 



This species has a close general resemblance to Margarita oT)- 

 scura, Couth,, but that is smaller, of slower increase, has an open 

 umbilicus, is very dull in colour, and the whole minute system of 

 spirals is different and much fewer ; the tubercled spiral in particu- 

 lar is the second, not the first as here, and is not close to the suture. 

 Than M. poculosa, Gould, which it resembles in its style of spirals, 

 this is more discoidal, especially is this more tabulated below the 

 suture than that ; the angulation here is on the upper, not on the 

 lower part of the whorls, and in that the infrasutural thread is 

 not beaded. 



16. TnocHUS (Maegakita ?) scintillaks, W. 



St. 24. Mar. 25, 1873. Culebra Island, vSt. Thomas, Danish 

 "West Indies. 390 fms. Mud. 5 young specimens. 



St. 56. May 29, 1873. Bermudas. 1075 fms. Gloh'r/erina- 

 ooze. 1 specimen. 



Shell. — Small, thin, white, very depressedly conoidal, angulated, 

 tumid on the base, umbilicated; mouth semioval. Sculpture. It 

 is perfectly smooth but for some curved puckerings which radiate 

 from the umbilicus but very soon die out ; above the middle the 

 body-whorl is roundly angulated. \Colour pure white, with a 

 transparent calcareous layer" over brilliant fiery pearly nacre. 

 Spire very flatly conical. Apex bluntly rounded, with a minute, 

 hyaline, depressed embryonic tip. Whorls 4|, barely rounded. 

 Suture slightly depressed. Mouth semioval. Outer lip thin, 



