TERTIARY MOLLUSCA. 125 



Turbo antiguensis, new species. 

 (Plate 5, Figures 4 o-c.) 



The following is a description of this species: 



Spire moderately elevated, imperf orate; whorls convex, with greatest 

 diameter below the middle of the whorl; suture impressed; surface covered 

 with revolving rows of nodules, about 20 on the body-whorl; on the body- 

 whorl the nodules of the 3 or 4 rows nearest to the suture are elongated 

 obliquely and fused with those of the adjacent rows, producing falsely pro- 

 tractive ribbing; remaining nodular rows alternating in size; secondary sculp- 

 ture of fine revolving threads within the internodular and interfilar spaces on 

 the base, but not crossing the nodes. 



Alt., 23 mm.; diam., 24 mm. 



This species resembles in shape and size Turbo crenorugatus Heilprin 

 from the Tampa "silex" bed, but is differently sculptured; it is probably 

 related to the unfigured T. dominicensis Gabb from Santo Domingo. 



Locality. Rifle Butts, Antigua, station 6854, Vaughan. 



Geologic horizon. Oligocene. 



Type.U. S. Nat. Mus. No. 167034. 



Turbo species. 

 The following is a partial description of this species : 



One mold of a Turbo with a high spire. The sculpture of the whorls above 

 the carina is indistinct, but several revolving threads are visible. The base 

 of the shell is ornamented with 4 or 5 strong revolving threads between which 

 are several smaller beaded threads. The basal fascicle 'is rather large and 

 prominent. 



Alt., about 23 mm.; diam., about 20 mm. 



This species is quite distinct from T. antiguensis and T. crenorugatus 

 and appears to be undescribed. 



Locality. Consolacion del Sur, Cuba, station 3474, the Alcalde, 

 collector. 



Geologic horizon. Oligocene. 



Margarita naticoides, new species. 



(Plate 5, Figures 5 a, 6.) 

 The following is a description of this species : 



Shell naticoid, polished, pearly within, smooth except for fine growth-lines; 

 whorls 3J, strongly convex anteriorly, but flattened or slightly concave in 

 front of the suture; suture distinct; spire low; base convex; aperture circular; 

 outer lip attenuated, inner lip incrassated; umbilicus rudimentary. 



Alt., 10.5 mm.; width, 11.4 mm.; length of aperture, 8 mm. 



Locality. Angela Elmira asphalt mine, near Bejucal, Cuba, stations 

 3652, 5312, Wiebusch, collector. 

 Geologic horizon. Oligocene? 

 Type.U. S. Nat. Mus. No. 167028. 



