192 ROBERT I'AYNE BIGELOW ON 



Withiu this limited area there were countless numbers of them, and in many places they 

 were so thickly spread that their margins touched upon all sides, or even overlapped. 



The spectacle presented by this collection of medusae was truly marvelous ; and in 

 order to show something of it to the rest of us, Dr. Field gathered a pailful of specimens 

 and brought them to the laboratory. Upon examination they were all found to belong to 

 a single new species of Cassiopea, — a genus of which only one species was known to 

 occur outside of the Red Sea, Indian Ocean, and soutliwest Pacific ; ^ and this pailful, 

 taken up at random, contained both adults and young in various stages of growth. 



Professor Brooks made drawings of some of these, and then I made a visit to the 

 Salt Pond to obtain more of the young medusae, and at the same time I collected sub- 

 merged bits of wood and stems of plants. My hopes were more than realized when, upon 

 examining these objects in the laboratory, I found them thickly studded in places with 

 scyphistomas in various stages of development. I was particularly delighted when I 

 noticed in one of the largest larvae certain glistening spots in the bases of the tentacles 

 and found, on putting them under the microscope, that they were unmistakably masses of 

 calcareous bodies that would form part of the marginal sense organs of the adult. They 

 excited my interest, especially as I had been studying the development of these structures 

 in Discomedusae ('90), and had been unal^le hitherto to obtain the early stages. 



After this discovery I began, with the advice of Professor Brooks, to make a careful 

 study of this species, with the intention of carrying the investigation of its anatomy and 

 development as far as the limited amount of time at my command would allow. Prelim- 

 inary accounts of my results were published in 1802 (Bigelow, '92, a, h and c) . In the 

 spring of 1893 I had another opportunity to visit Port Henderson with a party from the 

 Johns Hopkins University, and was able to make important additions to my earlier 

 observations. 



During the first visit to Jamaica I was unable to find Cassiopea outside of the one 

 locality that I have described, and, although l^otli the adults and the young in nearly all 

 stages were present at this place in such great numbers, searches for males and for females 

 with ripe eggs were equally fruitless. The great abundance of young and the range in 

 their apparent ages w\as, therefore, surprising, until I found that the scyphistomas were 

 multiplying freely by budding, in a manner to be described later on. During my second 

 visit I found this species as abundant as ever in this locality, and I also found a number of 

 adult specimens in several of the small shallow lagoons among the mangroves in the rear 

 of Port Royal. But these were all females, and it was still impossible to obtain males 

 or eggs that would develop. 



' Although Fewkes ('82) identifies his Cassiopea frondosa Lamarcli, of Key West and the Tortugas, witli Poli/chnia 

 frondosa Ag., it is nevertheless a true Cassiopea, not a Polyclonia. 



