TERTIARY MOLLUSCA. 121 



Turritella forresti Brown. 

 (Plate 4, Figures 5, 6, 7.) 

 Turritella forresti Brown, Proc. Acad. Nat. Sci. Phila., p. 613, plate 20, figs. 2, 3, 4, 7, 8, 1913' 



The following is the original description of this species: 



"Shell elongate, slowly tapering, of many whorls, with a raised sculpture 

 of three major spiral ridges, of which the one towards the apex is double and 

 beaded, the next one is at first single, but later becomes double and beaded, 

 while the third is, in the younger stage, not beaded. Between these major 

 revolving spiral ridges are finer revolving spirals, about five between the first 

 and second major spirals, and the same number between the second and third 

 spirals, with a like number from the third spiral to the suture. These second- 

 ary spirals may become knotty and beaded when crossed by the diagonal 

 growth lines, and the doubling of the major spirals comes from one of these 

 minor spirals becoming enlarged on that side of the major spiral towards the 

 apex. The suture becomes depressed by the shell being excavated above the 

 suture or on the basal side of the whorl. A fragment of 14 mm. tapers from 4 

 mm. to 2 mm. in six whorls. A larger fragment tapers from 6 mm. to 4 mm. 

 in a length of 13 mm." 



Localities. North of the cathedral, St. Johns, Antigua, station 6866, 

 Vaughan; Willoughby Bay, Antigua, Brown. 

 Geologic horizon. Oligocene. 

 Types. Philadelphia Academy, No. 1644. 

 Figured specimens. U. S. Nat. Mus. No. 167005. 



Turritella crocus, new species. 

 (Plate 4, Figure 8.) 



The following is a description of this species : 



Shell acute-conic; whorls nearly twice as wide as high, with 2 strong, high, 

 revolving ribs separated by a deep, evenly concave depression; anterior rib 

 round to acutish, with concave slope to the suture; posterior rib round, with 

 flattish posterior slope to the suture; suture deeply impressed; obscure traces 

 of revolving, impressed lines on median depression and on posterior rib; base 

 nearly flat; aperture oval or subquadrangular. 



Alt. of decollated specimen, 4 whorls remaining, 28 mm.; diam. of body- 

 whorl, 11.9 mm. The body-whorl of a larger specimen measures 18.5 mm. 

 in diameter. 



The median groove of this species recalls T. ambulacrum Sby., but 

 comparison shows the latter to be entirely distinct. 



A very closely related, if not identical, species occurs in limestone 

 at "E-l Salts," Chiapas, Mexico, in the area marked as Pliocene by 

 Bose. 



Localities. Upper bed at Crocus Bay, Anguilla, stations 6967 (type), 

 6894, and 6893. A fragment, apparently of T. crocus, was found at 

 Willoughby Bay, Antigua, station 6881, and another, possibly of the 

 same species, near Jackass Point, St. Johns Bay, Antigua, station 6865. 



Geologic horizon. Oligocene. 



Type.U. S. Nat. Mus. No. 167000. 



