142 A. E. Yerrill — Bermudian and West Indian Reef Corals. 



Agaricia fragilis Dana. Hat Coral. Shade Coral. 



Agaricia (Mycedia) fragilis Dana, Zooph. U. States Expl. Exp., p. 341, 1846. 

 Myceclium fragile Verrill, Bull. Mns. Comp. Zool., i, p. 55, 1864. Pourtales, 



Deep Sea Corals, pp. 48, 82, 1871. Florida Reefs Corals, pi. xi, figs. 1-10 



(series of young), pi. xiii, figs. 1-5 (adult), pi. xiv, figs. 1-9 (details), 1880. 

 Mycedia fragilis Edw. and Haime, Corall., iii, j). 83, 1860. 

 ? Agaricia Lamarcki and PA. imdata {non Ellis and Sol.) Edw. and Haime, 



Hist. Corall., iii, pp. 82, 83, 1860. 

 Agaricia fragilis Quelcli, Challenger Voy., Zool., xvi, p. 116, 1886. Vaughan, 



op. cit., p. 67, 1901. 

 Agaricia elephantotus (pars) Gregory, Quart. Journ. Geol. Soc. London, li, p. 



280, 1895 {non Pallas). 



Plate XXVI. Figures Ict-lrf. 



This elegant species has been so fully and beautifully illustrated 

 by Sonrel in the plates of the Florida Corals Reefs, by Louis Agassiz, 

 edited by Pourtales, quoted above, that little need be added, except 

 as to its synonymy and habits, and some special variations. It is the 

 onl^ species of Agaricia found at the Bermudas, where it is yerj 

 common in very shallow water, as well as in two to four fathoms. 

 So that Gregory's idea that it is a deep water variety is not valid. 

 In Harrington Sound, where there is scarcely any tide, it can often 

 be gathered by hand from water not over a foot deep, especially 

 under the shade of overhanging cliffs, but it is most abundant in 

 six to twelve feet of water. It generally lives in sheltered localities, 

 where heavy surf does not occur. It often occurs in colonies. 



In the spring of 1901, many recently dead and partly dead speci- 

 mens, mostly of large size, were seen in Harrington Sound. This 

 was due, without doubt, to a period of unusually cold and stormy 

 weather in February and March, which also killed vast numbers of 

 fishes, etc., in Bermuda waters.* 



ISTo forms like 31. elephantotus, nor like A. agaricites, are ever 

 found here, which is good evidence that they are distinct and more 

 tropical species. 



Hundreds of specimens from Bermuda, studied by me, show but 

 slight variations, aside from those due to ordinary growth and to 

 injuries. The specimens here are always pedicelled, with a broad, 

 thin, delicate, cup-shaped, saucer-shaped, or salver-shaped frond, 

 when normally grown ; rarely the edges bend down all around, and 

 the upper side may then be ilat or concave. After injuries the frond 

 may become irregular, or even much deformed, owing to unequal 

 repairs, but it never becomes truly encrusting. 



* See Amer. Journ. Sci., xii, p. 88, 1901. 



