DEPARTMENT OF MARINE BIOLOGY. 173 



herewith, for further discussion of this problem, which is now being 

 studied in various aspects by Doctors Vaughan and Tashiro, and by the 

 Director at Tortugas. 



The Pacific reefs are distinguished from those of the Atlantic by their 

 lithothamnion ridge, forming a breakwater along the crest of the sea 

 face of the reef often nearly a foot above low-tide level. Also, there are 

 about twice as many species of reef corals in the Pacific as in the Atlan- 

 tic, and some of these grow in abundance at depths below those in which 

 the Atlantic forms are common. Gorgonians are by no means so com- 

 mon over the Pacific as over the Atlantic reefs, but the fleshy alcyo- 

 naria, such as Sarcophyton, often carpet wide areas over the reef-flats of 

 the Pacific. It may be of interest here to observe that Dr. L. R. Gary, 

 as a result of his studies at Tortugas this summer, is enabled to state 

 that the calcareous spicules of gorgonians contribute more limestone 

 to the reefs than do the skeletons of the madreporian corals. 



It is deeply to be regretted that illness prevented Dr. T. Wayland 

 Vaughan from accompanying the expedition and continuing in the 

 Pacific the excellent work he has performed upon the reefs of the West 

 Indian region, and it was because of the absence of Dr. Vaughan that 

 the Director felt compelled to attempt the study of the corals of Torres 

 Straits. 



Professor David H. Tennent, of Bryn Mawr Gollege, succeeded 

 in effecting a hybrid cross between a male crinoid Comatula purpurea 

 and a female Echinaster, and he raised the larvae to a more advanced 

 stage than had hitherto been done; but the reciprocal cross could 

 not be made, for it being the spring of the year (September and October), 

 the eggs of the crinoids were not yet ripe. Later, at Badu Island, 

 Professor Tennent made a detailed study of Laganum and Salamacis, 

 the larval development of Vv'hich had hitherto been unknown, and he 

 also observed the early parthenogenetic development of these forms. 

 It is hoped that he may return to Torres Straits in the height of the 

 echinoderm breeding-season, for he is now prepared to conduct an impor- 

 tant research upon these forms. As in Professor Tennent's case, so has 

 it usually been at Tortugas. During the first season an investigator 

 commonly succeeds only in discovering the material or in developing 

 the method for some important study, and only upon his succeeding 

 visit is a well-rounded research produced. 



By making use of mosquito bars and by taking other precautions, we 

 were enabled to avoid the malarial fever of the Murray Islands and of 

 New Guinea. Two members of the expedition were, however, affected 

 with the "New Guinea ulcers," so much dreaded by unacclimated 

 people in these regions, but fortunately these troubles did not arise until 

 after the scientific v»^ork of the expedition had been accomplished, and 

 in neither case was any permanent impairment of health sustained. 



