MUSEUM OF COMPARATIVE ZOOLOGY. 



97 



Species. 



Colangia simplex .... 

 Balanopliyllia fioridana . . 



" palifera . . 



Thecopsammia socialis . . 



'* tintiniiabuluni 



Trocliopsammia infundibulum 

 Dendrophyllia Goesi 



* ' alteniata 



" cyatlioides . 



** cornucopia . 



Stereopsammia rostiata . 



" profunda 



Bathyactis symmetrica . . 



Diaseris crisi)a 



" pusilla .... 

 Guynia annulata .... 

 Duncania barbadensis 

 Haplopliyllia paradoxa . . 

 Anthemiphyllia patera . 



Total, — 64 species . 



Range in 

 Depth. 



Fathoms. 

 80-100 

 26-100 

 36-458 

 195-262 

 120-539 

 291-805 

 250-400 

 150-189 



270 

 73-400 

 164-805 

 539-805 

 116-805 

 119-189 

 119-189 

 100-357 

 103-191 



324 

 250-400 



9 O G ^ 



13 



2 .§ ^ 



c '"' c3 a; 

 ? c =" . 



o Oi 



f3 . = 



OJ 





12 



The total of sixty-four species is nearly as large as the total of the 

 shoal-water or reef corals of the same region, if we reduce the number 

 of the latter, as given by Duchassaing and Michelotti, to its proper 

 proportions by the rejection of merely nominal species. 



The proportion of simple forms to compoimd ones is very large, — 

 fifty of the former to fourteen of the latter. The compound ones 

 belong mostly to the families of Ocdlinidye, Stylophoridse, and Eupsam- 

 midse, with one species each from the Eusmilinse and Astrangiacese. 



Comparing this association with the one prevailing in the same seas 

 in shoal or moderately deep water, we find that there is not a single 

 species in common to both, and that they are separated by an almost 

 barren narrow zone. We find also that there is not a single simple 

 species in the shoal-water fiiuna, and that the compound forms belong 

 to the families of Astrseidse, Oculinidee, Fungidae, and Madreporidse, the 

 former preponderating by far. There are no Eupsammidee. The 

 nearest approaches between the two horizons would be as follows : 

 Madrepora cervicornis dredged living by myself in Barbados in 17 

 fathoms, Orhicella cavernosa in 15 fathoms in Florida, and Mycedium 

 fragile in 43 fathoms. The latter species comes in contact with the 



