272 



PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



The following is a description of the separates according to size, but the 

 percentage estimates are omitted, as accurate physical analyses of samples 

 are subsequently given: 



Held on jV mesh. 

 Held on jV mesh. 



Held 



on jis mesr 



Description of separates from bottom sample No. 777. 



Tests of Orhiculina adunca. 



Quantities of soft, non-indurated as well as indurated oolite grains, the 



former easily crushed by a touch with the point of a needle. Forami- 



nifera present. 

 Many perfect oolite grains; also foraminifera. 

 Many soft oolite grains; foraminifera; fragmental particles. 

 Held on ^^^ mesh. Small oolite grains and fragmental particles; material predominantly 



oolitic. 

 Passed 5J0 mesh. Quantities of small, globular bodies, minute oolites, and flocculent 



material. 



The separates were compared with the powder of the oolite forming 

 Golding Cay. The mud is clearly oolitic. 



The following are accurate physical analyses, made in the Bureau of 

 Soils, Department of Agriculture, of two specimens collected by Mr. Drew 

 in 191 2, and of sample No. 177, all of which are oolitic. Specimen No. 87 

 is from a depth of 7 feet, 2 miles west, and specimen No. 88 from a depth of 

 8 feet, 3 miles west of the west end of South Bight. 



Mechanical analyses of bottom specimens Nos. 87, 88, and lyf. 

 [Graphically illustrated on plate 94.] 



The calcium carbonate of the specimens comprises both aragonite and 

 calcite. 



Dr. Cushman has furnished the following lists of microzoa from samples 

 87 and 88: 



No. 87. A little fragmental calcium carbonate, occasional ostracod valves, and a few 

 foraminifera. 

 Clavulina angularis. Polystomella striatopunctata. 



Orbiculina adunca. Quinqueloculina, etc. 



Verneuilina affixa. 



No. 88. A few shell fragments, fragmental calcium, ostracod valves, and some foraminifera. 

 Orbiculina adunca. Verneuilina affixa. 



Peneroplis pertusus. Polystomella striatopunctata. 



Peneroplis pertusus var. discoideus. Quinqueloculina and Triloculina. 



The results of a chemical analysis of specimen 87 are given on page 269. 



The mechanical analyses give the following percentages of silt and clay 



for the three samples: No. 87, 61.2 per cent; No. 88, 49.8 per cent; No. 177, 



