62 



CEYLON PEARL OYSTER REPORT. 



A single haul (the second) in the middle of the area in question gave us nearly 

 2 cwt. of pearl oysters, large (3 years old) and small (6 months). Most of them were 

 attached to fragments of worn coral or to one another. 



Two hauls of the dredge upon the northern end of the Cheval region, depth 

 63- fathoms, gave much the same hottom and result, but with fewer living pearl 

 oysters. The sea-temperature this day was, at 7 a.m., 78*3 F., and at 9 p.m., 79'5 F., 

 and the specific gravity on both occasions 1"023, at anchor on the South Cheval. The 

 following day (28th) the temperature, at 7 A.M., was 78 F., and at 6 p.m. it was 

 79 "3 F. on the South-east Cheval. The specific gravity was still 1'023. 



We now had various sets of pearl oysters under close observation in our wooden 

 tanks, glass aquaria, and sea- water baths, on both the barque and the " Lady 

 Havelock," in order to test powers of detaching and travelling and re-attaching, 

 regeneration of the byssus when cut and when torn out, and similar matters; but 

 the results of these experiments will lie given separately further on in the report. 



On the morning of February 28th we (in the "Serendib") traversed from south to 

 north the inspection circle (l|- miles in diameter) which covered the southern end of 

 the East Cheval, 18 dives being taken at about equidistant points with the following- 

 results. This will serve as an example of the many lines of dives we traversed during 

 the next few weeks. 



The large Hydroid Zoophyte Campanvlaria juncea, which grows in tufts a foot in 

 height and looks somewhat like old withered masses of heather, is very characteristic 

 of this East Cheval paar. The beautiful large pinnate Halicornaria insignis is also 

 found here, and usually bears the protectively-striped Avicula zebra which is almost 



