2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 



fered many helpful suggestions and able assistance in the field, I owe 

 my sincere thanks. Capt. H. Glas of the Shang Wheeler, a research 

 vessel of the U. S. Fish and Wildlife Service at Milford, Conn., was 

 most helpful in the field. Thanks are due also to Dr. A. McCrone, who 

 arranged for a cruise aboard a New York University research vessel 

 in July 1961. Dr. H. Seal kindly gave advice on statistical methods, 

 and Dr. J. E. Sanders placed some valuable equipment at the writer's 

 disposal. Ruth Todd and Dr. J. F. Mello's constructive criticism 

 of the manuscript was most helpful. The Foraminifera were illus- 

 trated by Lawrence B. Isham, scientific illustrator, U. S. National 

 Museum. Figured specimens are deposited at the U. S. National 

 Museum. 



The research was supported in part by grants from the Sigma Xi- 

 RESA Research Fund and the Schuchert Fund of Yale Peabody 

 Museum. 



Previous Work 



OCEANOGRAPHY 



One of the reasons why L.I.S. was chosen for the present study is 

 that it is a relatively well known body of water. Riley (1952) 

 studied the hydrography of Long Island and Block Island Sounds. 

 Riley and others (1956 and 1959) have studied the physical and 

 chemical oceanography as well as some of the flora and fauna of 

 L.I.S. Some aspects of their work pertinent to the area of the present 

 study are described below. 



Temperature. — The temperature ranges from a minimum of about 

 2°C. in midwinter to a maximum of about 25 °C. in late summer. 

 The temperature gradient from surface to bottom is nearly vertical 

 from August to March, whereas a negative gradient, not exceeding 

 5°C, is present from March to August. 



Salinity. — The salinity varies from a spring minimum of about 

 25% to an autumn maximum of 29% . Because the effect of fresh- 

 water drainage is more pronounced in the narrow western portion, it 

 is often 3%o fresher than the central area. The salinity between top 

 and bottom water usually varies not more than 1% . Fresh-water 

 drainage into L.I.S. is mainly from the Connecticut drainage basin; 

 this fresh water moves eastward and out of L.I.S., being replenished 

 by bottom water entering from Block Island Sound. 



Oxygen. — Minimum values for oxygen are found in summer. 

 During autumn and winter oxygen is just slightly undersaturated from 

 the surface to the bottom. The minimum values for bottom water are 



