606 



SCIENCE. 



[N. S. Vol.. XIX. No. 482. 



main, for the explorations of the winter. The 

 laboratory was again opened in the boat-house, 

 partially equipped and courteously placed at 

 the disposal of the Chamber of Commerce by 

 the Coronado Beach Company. The labora- 

 tory was fortunate in again securing the serv- 

 ices of Mr. Manuel Cabral as collector, and 

 the power boat St. Joseph, by means of which 

 it was possible to have collections made in the 

 early morning ten to fifteen miles off shore 

 from Coronado brought to the laboratory 

 early in the forenoon for the day's work. 



The climatic conditions were ideal for win- 

 ter work. Bright sunshine every day and an 

 equable temperature obviated the necessity of 

 artificial heat in the laboratory, and no storms 

 interfered with the regular trips of the col- 

 lector. Tides at this season of the year are 

 also favorable, reaching lowest levels in the 

 afternoon, while in the summer the best tides 

 for shore collecting all occur before daybreak 

 or early in the morning. The persons en- 

 gaged in the survey and subjects of their 

 investigations were as follows: Professor W. 

 E. Eitter, director of the laboratory, Balan- 

 oglossus, Tornaria, pelagic and littoral tuni- 

 cates; Assistant Professor Charles Kofoid, 

 pelagic Protozoa; Dr. Alice Robertson, Bry- 

 ozoa and Copepoda; Mr. L. IT. Miller, assist- 

 ant in zoology, and Mr. E. D. "Williams, a 

 graduate student, working with Professor 

 Kofoid on the Protozoa and Miss Margaret 

 Henderson continuing her work of last sum- 

 mer with Dr. IT. B. Torrey, on the pelagic 

 Coelenterata. 



The physical observations made in the pre- 

 vious summer by Mr. H. M. Evans on tem- 

 peratures and salinity were continued this 

 winter by Professor W. T. Skilling, of the 

 San Diego Normal School. These observa- 

 tions show, as might be expected, that the 

 shallow bay waters have cooled down more 

 than the surface waters of the adjacent ocean. 

 Whereas last summer the bay waters were 

 4°-5° 0. warmer than the ocean, they were in 

 midwinter l°-2° cooler. Temperature in sura- 

 mer in the bay ranged from 22.7° to 26.7°, 

 in winter from 13.3° to 14.7° C. Surface 

 waters in the adjacent ocean in summer 



ranged from 18° to 22.5° except during a cold 

 spell August 27-31, when they fell as low as 

 14.8°. In winter the range was from 14.6° 

 to 15.6°. 



The salinity also declined slightly below the 

 summer determinations, the average of the 

 readings, reduced to Dittmar's standard, of 

 ocean water (at Coronado pier falling from 

 1.02455 to 1.023748; of the middle portion 

 of the bay near the mouth of Glorietta Bight 

 at Coronado falling from 1.02546 to 1.024274. 

 Determinations of salinity were also made in 

 the mid-channel between Coronado and San 

 Diego at the ferry crossing, yielding an aver- 

 age of 1.023927. 



The biological explorations of the winter 

 were again directed in the main to the plank- 

 ton. Quantitative examinations were made 

 of the plankton of the Bay of San Diego near 

 the laboratory and of Glorietta Bight. Sur- 

 face waters of the ocean off-shore from Coro- 

 nado were also examined, but the principal 

 field of operations was ' Cabral's bank,' an 

 uncharted area about ten miles off Point 

 Loma with 60-90 fathoms of water, known 

 to local fishermen. A number of hauls were 

 also made in the adjacent deeper waters of 

 the Coronado submerged valley.* In all of 

 these localities there was a noticeable decrease 

 in the quantity of the plankton as compared 

 with that taken in similar hauls of our nets 

 in midsummer. There was a marked dim- 

 inution in the quantity of diatoms and a still 

 more pronounced reduction in the volume and 

 variety of the Peridinida. Oonyaulax, which 

 was so abundant in August as to color the 

 water and cause an appreciable odor along 

 shore, was found in living condition but a 

 few times though empty skeletons were still 

 not infrequent. The Tintirnidae, on the other 

 hand, were abundant in the ocean waters and 

 showed marked increase over summer ratios 

 in the bay. The Eadiolaria were also, rela- 

 tively to summer conditions, greatly increased 

 in numbers and variety in all collections made 

 some distance off shore, but were not common 



* George Davidson. ' The Submerged Valleys of 

 the Coast of California, U. S. A., and of Lower 

 California, Mexico.' Proc. Calif. Acad. Sei. Geol., 

 Third Ser., Vol. I, pp. 73-103, Pis. 2-10, 1897. 



