SUPPLEMENT.— HYATTINA. Mi 



Note. — Costae give way to striae at a diameter of about 75 mm. 

 Distinction. — From Wilsoni, smaller umbilicus, earlier failure of costse. 

 Locality and Stratum. — Dorset : Bradford Abbas, and by matrix certainly from 

 Paving Bed. 



Date of Existence. — Bradfordensis, or Murchisonse bemera. 



XVI. Genus — Hyattina, 8. Buckman. 



(Type — Hyattina Brasili, sp. n.) 



Definition. — Platyleptogyral, angustumbilicate ; subdensiseptate, 

 brevi-angustilobate; laterally subflexiradiate ; peripherally angulira- 

 diate, subtabulate, parvi-nonsepti-carinate. 



Remarks. — There is but little curvature in the course of the 

 costce on the lateral area. Other noticeable features in combination 

 therewith are the small umbilicus, the compression, the subtabulate 

 periphery, and the short, narrow lobes of the suture-line. Fig. u.— Radial 



Distinction. — From the genera which it resembles in the course of me °jBrJui. 

 the radial line, it is distinguished by the combination of characters 

 noticed above. The brevi-angustilobate, densiseptate character of the suture-line 

 is, perhaps, most distinctive. 



1. Hyattina Brasili, 8. Buckman. Suppl., Plate XIII, figs. 7 — 9. 



Description. — Platyleptogyral, angustumbilicate, costate ; periphery sub- 

 tabulate. 



Localities and Strata. — Somerset : Haselbury, near Crewkerne, from the 

 "lower beds." Foreign: Normandy (Calvados), Feuguerolles, two specimens 

 (one from M. L. Brasil, labelled " Murchisonse beds ''). 



Date of Existence. — Murchisonse hemera. 



