SMITHSONIAN EXPLORATIONS, I927 57 



interesting variations in the anatomy of these creatures produced hy 

 hybridization. 



A series of specimens of Ccrion viarcgis Bartsch and Ccvion 

 incannm Binney were sent to Professor Charles Jeffreys, Harvard 

 University, Cambridge, Massachusetts, for Chromosome studies. To 

 these will shortly be added a series of the hybrids of these two species 

 produced in the Newfound Harbor Key colony, for the same purpose. 



Dr. Carlos de la Torre, of Havana, called my attention to a wild 

 native hybrid of Ccrion tridcntatuui and Ccvion paracuta which oc- 

 curs on the UDrth coast of Cuba at Playa de IMuerto a little west of 

 Bahia de Jaruco. Under the guidance of vSr. Guillermo Aguayo, I 

 visited the place and made a large gathering of specimens of both 

 parents and hybrids. A series of these are now being dissected by 

 students of mine at George Washington University, and specimens 

 have also been sent to Professor Jeffreys for Chromosome study. 

 The general jjicture presented bv this native hylirid colony is similar 

 tO' that which we produced by crossing Ccrion viarcgis and Ccrion 

 incanuni on Newfound Plarbor Key, Florida. 



UNDERSEA ECOLOGY 



The Tortugas region of the Florida Kexs was long known as pre- 

 senting one of the richest faunal asseml)lages on the Atlantic coast. 

 For reasons not as yet entirely solved, but probalily involving a num- 

 ber of factors, this fauna became materially reduced, and even at 

 the present time, from a molluscan standpoint, is exceedingly poor. 



During our Philippine cruise in 1907 to IQIO, I became very much 

 interested in the possibility of taking undersea pictures to show the 

 ecologic conditions under which organisms exist, and during the 19 12 

 cruise to the Bahamas I took a series of photographs through a 

 truncate cone water glass from the surface. Later the development 

 of the diving hood presented new factors, because b\' means of this 

 apparatus one is alile to spend as much time as one chooses undersea 

 without great discomfort, and enjoy undersea rambles which give 

 one an entirely new concept of the adjustments of creatures to the 

 undersea environment. A view through a glass bottomed boat or 

 a water glass does not reveal the subsea atmosphere as it actually 

 exists, and }ou do not become conscious of this until you are actu- 

 ally undersea and looking in a horizontal direction, for then you at 

 once become aware of the significance of the silvery sides of the 

 pelagic fishes which correspond beautifully with the general tone 

 of the background. 



Hurricanes destroyed the major portion of the Staghorn coral 

 reefs since our early visits to the Tortugas group, and these are now 



