ASTRALIUM. 22-? 



the umbilicus excavated, whitish, bounded by an intensely orange- 

 vermillion tract. Alt. 28, diam. 40 mill. 



West Indies ; Florida Keys (Simpson); Costa Rica; Venezuela. 

 T. aurispigmentmn Jonas is synonymous. 



It is frequently larger than I have indicated. 



A. LATispiNA Phil., 1844. PI. 63, figs. 21, 22. 



Shell imperforate, conic, greenish, brown maculated ; whorls 7, 

 subplanate, obliquely costulate below the sutures, then with two 

 beaded spiral lirae ; margins of whorls exserted, expanded, com- 

 pressed, armed with triangular spines ; last whorl sharply carinate ; 

 base radiately lamellose and ornamented with three or four granose 

 concentric costse; umbilical area depressed, pale greenish or yellow- 

 ish, aperture oblique, angulate. Alt. 35, diam. 50 mill. 



Gulf of Mexico to Rio Janeiro. 



Operculum oval, outside white, smooth, with a single arcuate 

 wide rib ; inside flat, chestnut colored, nucleus submai'ginal. 



T. huschi Kiener, and T. tentorium Anton are synonyms. 



This form I have not satisfactorily identified with any shells I 

 have seen. It seems to be closely allied to the preceding species. 



Subgenus Lithopoma Gray, 1850. 



Shell turbinate or trochifonn, elevated, imperforate, periphery^ 

 carinated or rounded, whorls above radiately plicate ; oj^erculuni 

 oval, outside coarsely granulose, and either simply convex or with a 

 curved spiral rib with its terminations connected by a straight one; 

 nucleus submarginal. West Indian Province. 



A. Turbinate species tviih rounded peripherij. 

 A. TUBER Linn., 1767. PL 56, figs. 79, 80. 



Shell turbinate-conic, imperforate, ver}^ solid, dirty white or pale 

 green, radiately maculated with brown above, irregularly marked 

 and lighter below ; whorls 6, upper two smooth by erosion, the fol- 

 lowing obliquely coarsely plicate and finely wrinkled in the same 

 direction above, somewhat shouldered, obtusely angular near per- 

 iphery, above which several obscure beaded lirse revolve, shagreeii- 

 ed by intersection of incremental strise and oblique wrinkles ; base 

 nearly smooth ; aperture very oblique, oval, silvery within ; colu- 

 mella short, wide, generally bituberculate at the base, exca;vated 

 over the location of the umbilicus. Alt. 45, diam. 50 mill. 



West Indian Province ; Florida 



