SECRETARY'S REPORT 25 



Department of Biological Sciences, University of Delaware, ichthy- 

 ologist and ecologist, whose chief interest was in making an ecological 

 study of a mangrove swamp and its associated fish population; and 

 Dr. Edward L. Bousfield, curator of invertebrate zoology. National 

 Museum of Canada, a carcinologist specializing on barnacles and 

 ampliipod crustaceans. 



The expedition sailed on March 20 from Miami with Drs. Rehder 

 and Schmitt and the expedition's collecting outfit, arriving in 

 Progreso, Yucatan, a iew days later. There Drs. Clarke, Daiber, and 

 Bousfield joined the expedition, which departed on March 26 for 

 Isla ]\Iujeres, where they spent a few days gathering shallow-water 

 animal life and algae. From here the party went to San Miguel, 

 Isla Cozumel, for the first three days of April. At this locality they 

 made collections on the coast and also along shore by diving and with 

 the electric light and dipnet over the ship's side at night. They spent 

 the next few days reconnoitering Espiritu Santo and Ascension Bays 

 and collected at the northern end of Cozumel from shore out to a 

 depth of two fathoms, by diving, and also at Punta Molas, near the 

 lighthouse, and in the shallow brackish lagoon at the northern end 

 of Cozumel. 



The period April 10 to 19 was devoted primarily to Dr. Daiber's 

 ecological study of portions of the great mangrove swamp in Ascen- 

 sion Bay. Concomitantly extensive invertebrate and entomological 

 collections were made on land and along shore in the vicinity of the 

 lighthouse, in the swampy areas, on the far shore of the Bay, and 

 at the northern end of the reef where it joins the mainland. The 

 shoal waters of the south end of Cozumel Island, particularly about 

 Punta Santa Maria, also were explored. 



Members of the party flew to Merida on April 24 to meet J. Bruce 

 Bredin, sponsor of the expedition, and Ernest N. May, both of Wil- 

 mington, Del. Although Drs. Clarke and Bousfield had to leave the 

 expedition at this point, the rest spent April 25 to 27 visiting the 

 Maya ruins at Chichen Itza, and on April 28 those at Uxmal, return- 

 ing to Cozumel on April 30. They then departed for Georgetown, 

 Grand Cayman, and after a limited period of collecting on this island, 

 returned to Miami on May 7. 



In the course of the six weeks' expedition 119 collecting stations 

 were established, mostly in the marine littoral, and 15 plankton sam- 

 ples were made with tow and dipnet, the latter with the aid of a 

 submerged electric light over the ship's side. Dr. Clarke at 20 dif- 

 ferent places collected insects, along with other terrestrial arthropods, 

 and, on Cozumel, a num.ber of bats. The number of marine inverte- 

 brates obtained may total 10,000. Many of these are small, some of 

 even microscopic size. Over 500 specimens of fishes were caught, and 

 in excess of 6,000 insects and terrestrial arthropods were preserved. 



