132 THK XAlTrLU>*. 



Later Eocene. 



Vicksburg group (Jackson, Vicksburg and Salt Hill formations). 

 (Icala group (Nummulilic beds of Florida). 



MIOCENE. 

 Chipola Epoch. 



Chattalioochee group (Hawthorne and Ocheesee beds). 

 Tampa group (Shiloli marl, Tampa and Chipola beds). 



Chesapeake Epoch. 



Chesapeake group (Maryland, Virginia, etc.). 



Grand Gulf group (Grand Gulf beds, Altamaha Grit, etc. — Epoch of elevation 

 begun and in progress). 



PLIOCENE. 

 Floridan Epoch. 



Lafayette group (Lagrange beds. Orange sand, etc.; culmination of elevation). 

 Floridian group (Caloosahatchie, De Solo and Waccamaw beds, etc.). 



PLEISTOCENE. 



Glacial Epoch. 



A FOURTH Supplement to the Fifth Volume of the Ter- 

 restrial AlR-BREATHIXG MOLLUSKS OF THE UnITED StATES, by 



W. G. Biiiney. (Bull. Mus. Conip. Zool. xxii, no. 4). Mr. Biuney's 

 .series of Supjjlevients has become one of the established Institutions 

 of our Conchological World. This last number is no less interesting 

 and useful than its predecessors. It contains a resume of systematic 

 work in this department from the date of the 3d supplement to July 

 1, 1891. Most of the descriptions of new forms have already 

 appeared or been noticed in the Nautilus, except the following : 

 Glaudina decussata var. Singleyana W. G. B., Central Texas ; 

 Zonites shepardi Hemphill, Santa Catalina I. ; Z. carolinensis Ckll., 

 Mts. of N. C. ; Z. diegoensis Hemphill, Julian City, San Diego Co., 

 Cal. ; Polygyra 7-volva var. Floriduna Hemph., Oyster Bay, Fla. ; 

 Papa coloradoensis Ckll., and a number of new color-varieties of 

 Patula and Aglaia. 



Mr. Binney gives generic diagnoses of the genera Pristiloma and 

 Pimcium, groups which he had formerly referred to Microphysa. 

 Much useful matter has been added to our knowledge of the West 

 Coast Slugs, the figures and anatomical details being especially 

 acceptable. The four plates illustrate the new species and varieties 

 described. There arc also numerous figures in the text. We con- 

 gratulate Mr. Binney on the completion of this supplement, and 

 hope that he will, in due time, give us still another. 



