16 NOETLING : MARINE FOSSILS FROM MIOCENE, UPPER BURMA. 



tunicaia ; the general shape and the sculpture of the right valve are 

 the same, but the left valve of Covbula tunicata shows near the 

 umbonal part a sculpture similar to that of the right valve, while 

 it is perfectly smooth in Covbula harpa. 



III.— GASTROPODA. 

 TROCHUS BUDDHA, Spec. nov. t Plate IV, Fig. i— 2a. 



The shell is depressed-pyramidal, perfectly flat on the base ; it 

 consists of at least six whorls which increase very slowly in height 

 and are very slightly concave ; suture sharply defined ; earlier whorls 

 perfectly smooth, but on the last, two fine, revolving ribs begin to 

 appear which also extend over the base ; that rib which is closest to 

 the suture is the strongest and separated from the next by a compara- 

 tively deep and broad furrow ; umbilicus narrow but deep. Aperture 

 unknown. 



Locality.—* Common at Minbu and Yenangyat. 



Remarks. — This species can be easily distinguished by its 

 apparently smooth surface, because the ribs become frequently 

 obsolete, together with the regularly ribbed base ; Trochus buddha 

 seems to be one of the smaller species, as the largest specimen 

 measures only 13 mm. diameter by 6 mm. height ; those of 1 1 mm. 

 diameter form the majority. 



TROCHUS BLANFORDI, Spec, nov., Plate IV, Fig. 3—40. 

 The shell is pyramidal, having a flat, sometimes slightly inflated 

 base ; the whorls are low, slightly concave, and show a very pretty 

 and characteristic sculpture ; beginning from the suture, there are 

 two keels, like strings of beads, the upper one a little stronger than 

 the lower one, separated by a rounded smooth furrow ; above those 

 the surface is slightly concave, and there are from two to four revolv- 

 ing lines of very regular small round tubercules, the lowest line of 

 which is generally the largest. On the base the sculpture consists 

 of numerous revolving ribs, which look like strings of beads; thinner 

 and thicker ribs alternate very regularly ; umbilicus very narrow ; 

 aperture unknown. 



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