ASTRALIUM. 227 



the folds generally eighteen to twenty in number on the last -whorl, 

 sub-interrnpted or excavated about the middle, produced at the 

 sharply carinate peri23hery into squamose square soniewhat descend- 

 ing spines ; base flattened, radiately striate, and with four to six 

 concentric irregular subnodose lirre ; aperture very oblique, wide : 

 lip scalloped, chanelled at outer angle ; columella bidentate below, 

 its face slightly grooved. Alt. 40, diam. 45 mill. 



Honduras (Reeve); West Indies. 

 T. corolkt Reeve is synonymous. 



A. TUBEROSUM Phil. PL 64, figs. 57, 58. 



This thick-shelled Trochid stands near to T. ccelatus, but is distin- 

 guished by the following characters ; the whorls are flat, not arched, 

 in the middle ; the superior nodules are situated near to the suture, 

 are hemi-sphserical and solid ; the last whorl has but a single row of 

 nodules ; the carina is sharper, the base flatter, with only three con- 

 centric nodose lirse ; the aperture is lower, more rhomboidal ; color 

 reddish brown, more or less vei'ging on violet. 



Coast of Mexico. 



I have translated from Philippi the more important portion of his 

 description. I am unable to identify the form with any shells I have 

 seen. It is 2:)robably immature. 



A. PLicATULUM Philippi. PI. 64, figs. 62, 68. 



Shell strictly conic, imperforate, yellowish white ; whorls planu- 

 late, the last acutely angled, obliquely plicate, the folds small, about 

 forty in number on the body-whorl, interrupted by two spiral fur- 

 rows, of which the upper is in middle of the Avhorl, the lower midway 

 between that and the wavy lower margin of the whorl ; base nearly 

 flat, with six strong, elevated concentric lirse, and radiating lamel- 

 lose strise, Alt. 23, diam. 25 mill. 



Habitat unknoivn. 



Known to me only by Philij^pi's figure and description from which 

 the above is taken. It j^robablj^ does not belong to this group. 



Subgenus Imperator, Montfort, 1810. 

 Shell large, trochiform, concave and umbilicate below, carinated 

 and spinose at periphery, whorls convex and granulose above ; oper- 

 culum oval, outside smooth, obsoletely uuicostate. 



Australo-Zealandic Province. 

 Canthorbis Swainson, 1840, and in part Guildfordia Gray, 1850, 

 are synonynis. 



