78 



SM ITHSONIAN INSTITUTION 



( )n Loggerhead Key the colonies of Ceriou casablancae and Cerion 

 viaregis are in excellent condition. The small colony of Ceriou in- 

 caiiuii! between the dining hall and the water tower is doing well. 

 From the mixed Colony I of Ceriou casablancae and C. viaregis I 

 gathered all the dead specimens — some 200 — in order to study them 

 at my leisure in Washington, to determine if the shells show any 

 signs of hybridization of these two species. The colony of Ceriou cras- 

 silabris from Porto Rico, while not in a flourishing state, is, never- 

 theless, holding its own. On Loggerhead Key all the other West 

 Indian transplants have disappeared, including the huge importation 

 of Ceriou uva from Curacao. 



Fig. 75. — Eight hybrids of Cerion incanum and 

 Ceriou viaregis produced in cages on Loggerhead 

 Key, Fla. 



The most interesting part of the Cerion problem, however, hinges 

 upon the low cages in each of which I had planted a specimen of 

 Ceriou viaregis and Cerion incanum. Here I obtained six adult speci- 

 mens of the first generation hybrids, one almost adult, and young 

 individuals. These we have planted in a similarly constructed cage, 

 6x6 feet in size, and it is hoped that we may obtain second generation 

 progeny from them. 



No survivors were found on all the little artificial islands which 

 have been reported upon previously. 



On Garden Key. I was greatly surprised to find three of the five 

 Cuban species planted on the parapet in 1924 thriving, namely, Cerion 



