DEPARTMENT OF MARINE BIOLOGY- III 



whole West Indies, we may expect that many of the forms collected at the 

 Tortugas are new to science. Very abundant is the genus Leptoclinum. 

 Next to it the Botryllidse are represented by a large number of prettily 

 colored forms ; most of them are probably only varieties of one and the same 

 species. Of other genera, hitherto not yet known from the West Indies, I 

 may mention Styela, Perophora, Stereoclavella, Polyclinum, Tolycitor, and 

 Di'plasoma, which are represented in my collections by one or several species. 

 Among the Styelid^ there are some very interesting forms belonging to the 

 subfamily of the Polyzainse. Besides these forms, most of the common and 

 well-known West Indies ascidians are also represented at the Tortugas ; for 

 example, ThaUusia nigra (synonymous to Ascidia atrales), Ascidia hygo- 

 miana, Ascidia curvata, Halocynthia riiseana, Polycarpa obtecta, and so on. 

 I was somewhat surprised not to find here the interesting tropical genus 

 Rhodosoma, which has been collected at different localities of the West Indies. 

 It was of especial interest to compare the marine fauna of the Tortugas 

 with that of St. Thomas, Barbados, and Jamaica, where I collected with 

 Professor Kirkenthal for about four months before I came to the Tortugas. 

 Generally speaking, the Httoral fauna of the whole West Indies seems to be 

 very uniform. There are many characteristic and typical forms widely dis- 

 tributed all over the West Indies, but at some places less abundant than at 

 others. Nevertheless, I noticed some remarkable differences between the 

 Tortugas and the other islands I visited. On the Tortugas reefs I found in 

 great abundance some species of ophiurans, which I did not collect at any 

 other place. On the other hand, the extremely common West Indian star- 

 fish Tentaceras reticulatus is very rare at the Tortugas, while other species, 

 for example Madrepora palmata and the yellow-colored form of Rhipido- 

 gorgia flahelhim, are entirely wanting. These are only a few examples, but 

 I hope to find an occasion, later on, to publish some more detailed facts, based 

 on the study of my collections. 



Mr. Davenport Hooker made some interesting observations upon the reac- 

 tions of the newly hatched loggerhead turtle, and presents the following pre- 

 liminary report: 



Preliminary Observations on the Behavior of Some Nezvly Hatched Logger- 

 head Turtles (Thalassochelys caretta), by Davenport Hooker, 

 Yale University. 



Inasmuch as there are prevalent various ideas concerning the action of 

 young sea-turtles in reaching the ocean after they are hatched, a series of 

 experiments was performed this past summer (1907) at the Marine Biological 

 Station of the Carnegie Institution of Washington at Tortugas, Florida, to 

 discover, if possible, just what factor or factors determine the behavior of the 

 loggerhead turtle in this respect, and to find out something about the early 

 habits of this species. By eliminating certain features, such as light, sight 

 of the ocean, etc., the following very definite results were obtained : 



( I ) Newly hatched loggerhead turtles have two inherent tendencies : first, 

 to enter hollows, and, second, to go toward the point of greatest illumination- 

 Both of these tendencies may act together to the slight detriment of the 

 second, but either one would eventually lead the animal to the sea, as the 

 shores always slope down to the water and the reflected light from the water 



8— YB 



