REPORT ON THE ACTINIANS OF PORTO RICO. 
By J. E. DUERDEN, Ph. D., A. R. C. Sc. (Lond.), 
Bruce Fellow , Johns Hopkins University. 
The collection of Actiniaria secured by the United States Fish Commission 
steamer Fish Hawk from around Porto Rico supplements in many ways the results 
of several recent writers on the West Indian Actinian fauna. Within the past few 
years Prof. J. P. McMurrieh (1889, 1889a, 1896, 1898) has studied the Actinians of 
the more northern Bahamas and Bermudas, and also a few specimens from Cuba; 
Prof. A. E. Verrill (1898, 1899, 1900) has added several species to the Bermudan list 
and introduced certain changes in nomenclature and synonymy; 1 have recorded nearly 
40 species from around Jamaica (1898, 1898a, 1900) and described the Zoanthece and 
Stichodactylinai more fully. Among older writers Lesueur (1817) described a number 
of species found mainly around the Lesser Antilles, but Duchassaing & Michelotti, 
in their “Memoire sur les Coralliaircs des Antilles” and “Supplement” (1860, 1866), 
first made known to any degree of completeness the peculiarities and richness of the 
Actinian fauna of this region. Dr. O. Carlgren (1900a) has recently had the oppor- 
tunity of examining in Turin the Aetiniarian collections of Duchassaing & Michelotti, 
and gives the relationship of several whose identity has been somewhat doubtful. The 
West Indian Actiniaria, including also those of the Bermudas, are now probably as well 
known as those of most areas, although owing to the incompleteness of the description 
of many of the eai’lier species, and the difficulties involved in the specific study of genera 
such as Palythoa and Zoanthus , many synonymic difficulties have been introduced. 
With two exceptions the species represented in the Fish Ilawk collections are 
such as occur in abundance in the shallow waters around Jamaica, and the majority 
are also recorded from the Bahamas and the Bermudas. One species, which I have 
named Bunodosoma spliendata , seems to be new, and such will probably be the case 
with a single specimen of Cerianthus. Already most of the others have been fully 
described and figured among the writings of the authors above mentioned, but in 
order to make the report more complete brief descriptions are again given, the details 
obtainable from the preserved material being supplemented by observations made on 
the living polyps elsewhere. 
Before proceeding with the description of the species some remarks are neces- 
sary upon the great changes which the classification of the Actiniaria is at present 
undergoing. All the most recent researches on their anatomy and development 
indicate that the Actinians are divisible into three main groups — Cerianthece , Zoan- 
thecu, and Ilexactiniai , and representatives of all these occur in the present collection. 
The subdivision is based upon the method of increase of the mesenteries beyond the 
primary pairs, the order being fundamentally different in the three groups, and 
leading to adult conditions of the highest significance in Actinozoan morphology. 
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