1913] REGION ABOUT NATAL, BRAZIL. 451 



This species is easily recognized by its very convex shape and 

 the distinct sculpturing which is on its sides. Delicately orna- 

 mented cup-shaped impressions, left in the finer siliceous parts of 

 the limestones, may be easily observed. 



Cerithium ( ?) sp. ind, 

 (Plate XX., Fig. 4-) 

 At the locality near Desterro were found impressions of a 

 Cerithium-like form unlike those found at the other localities. 

 Length, lo mm. to 12 mm. ; width of last volution, 3 or 4 mm. ; angle 

 of the spire, approximately 25°. The volutions are about 8 in 

 number, each convex in profile, and ornamented with spiral, slightly 

 dotted lines following around the volutions. The aperture was 

 not preserved in any of the specimens. 



TuRRiTELLA (?) Jacoouea Jenkins, new species. 

 (Plate XX., Figs. 7 and ya.) 



A broadly turreted form. The length is 25 or 30 mm. The 

 width of the last volution is 12 or 15 mm. There are 8 or 9 volu- 

 tions on the spire which comes to an angle of approximately 40°. 

 Each volution is slightly convex in profile. The ornamentation is 

 not distinctly visible on such poor material. There may be some 

 sort of ornamentation following the center of the volution. 



Many poor casts and impressions of these shells were found in the 

 sandy limestones of the quarries at Jacoca, four kilometers south- 

 west of Ceara-Mirim, Rio Grande do Norte. Inside casts show a 

 double spiral coil following the volutions. 



It is difficult to tell from such poor material whether or not this 

 is a Turritella. If it proves to be Nerinaea it may place the age 

 of the rocks in the Cretaceous. However this species is easily rec- 

 ognized by its broad form and may be of use in later correlation. 



Turritella natalensis Jenkins, new species. 

 (Plate XX., Figs. 6 and 6a.) 

 A small, slender shell about 35 mm. long. The longest found 

 was 50 mm. The diameter of the last volution is about 6 or 7 mm. 



