DEPARTMENT OF MARINE BIOLOGY. 207 



up a paper on the method of reproduction in the sharks of this region. The 

 indications are that all the sharks taken were viviparous. Three of these were 

 Galeocerdo tigrinus, one being a marked melanistic variation. There is now 

 at hand sufficient data for a careful description of this shark, that heretofore 

 given being very imperfect. The other sharks all belonged to the genus 

 Carcharhinus, one being a species apparently not recorded heretofore from 

 Florida, and another a species not yet identified. 



At Tortugas I got only three sharks in my two weeks' stay. One of these 

 was an unknown Carcharhinus, and the other a shark which we were unable to 

 classify by the use of Jordan and Evermann's Fishes of North and Middle 

 America. It is hoped that it may be a new species. Photographs, descrip- 

 tions, and measurements were made of all these doubtful specimens, and teeth 

 and pieces of skin were preserved for help in classification. Photographs 

 were also made of the reproductive apparatus and eggs of a nurse shark, 

 Ginglymostoma cirratum. These will be used to illustrate a forthcoming paper 

 on this shark. 



TELEOSTS. 



My time being almost entirely spent in fishing for sharks, not much attention 

 was given to the bony fishes. However, notes were made as heretofore on all 

 new or interesting forms which came in. With a view to a study of its natural 

 history, especial attention was paid to the Echeneis or Remora. A number of 

 very small specimens have been collected at Key West, and under the care of 

 a capable fisherman these are being added to, and it is hoped that this will be 

 the best collection of small specimens of Echeneis to be found anywhere. 

 It is known that the young fish differs considerably in the structure of its tail 

 from the adult, and it is hoped that this collection will enable one to deter- 

 mine the character of the change. 



Preliminary Report on the Chemistry of Light Production by Luminous Animals, 



by E. Newton Harvey. 



On June 26 the writer sailed for Havana, Cuba, to collect the Cuban cucullo, 

 a luminous elaterid beetle, Pyrophorus havatiiensis, reported abundant during 

 the summer in the cane regions near Havana. Headquarters were estabhshed 

 at the Agricultural Experiment Station at Santiago de las Vegas and trips 

 were made into the surrounding country to Guanajay and Giiines, and a five 

 days' excursion to the mountains in Pinar del Rio near Bacanagua. Unfor- 

 tunately, the height of the season (during May and June, depending on the 

 rains) for the beetles was past and not enough material could be obtained 

 for the carrying out of the chemical work intended. Preliminary studies were 

 undertaken and arrangements made for the shipping of beetles north to 

 Princeton during the height of the season next spring, when research will be 

 continued. I am deeply indebted to Dr. J. F. Crawley, Director of the 

 Experiment Station, and Mr. C. N. Ageton, of the chemical department, for 

 their kindness during my stay at Santiago de las Vegas. 



The proposed studj' of the West Indian cucullo is merel}' a continuation 

 of research on the chemistry of biophotogenesis in the common fire-fly and in 

 luminous bacteria on which the waiter has been engaged for the past two years. 

 Most favorable results have been obtained and an extensive investigation of 

 other luminous forms is planned. It can be stated definitely now that the 

 luminous substance is easily capable of solution and isolation, provided an 

 abundant supply of luminous material can be obtained. A phosphorescent 

 squid (such as that of Japan, or certain molluscs) seems most favorable, and 

 it is hoped that an opportunity of studying these forms Avill present itself in 

 the near future. 



