MUSEUM OF COMPARATIVE ZOOLOGY. 197 



CORALS. 



The rich collections made by Mr. A. Agassiz, in the United States 

 steamer " Blake," Commander Sigsbee, U. S. N., in the southern and 

 eastern part of the Gulf of Mexico, have yielded a number of interesting 

 forms of deep-sea corals, in addition to most of those already described 

 by me from those seas in former publications of the Museum. Mr. 

 Agassiz's dredgings extended farther to the westward and southward 

 and into greater depths than mine, thus giving a more complete view of 

 the distribution of deep-sea corals in that sea. As far as our present 

 knowledge goes, no sea-bottom can rival in abundance of deep-sea 

 corals the West-Indian. It is not at all unfrequent for a single cast 

 of the dredge to bring up a dozen different species, represented by 

 more or less numerous specimens of each. 



The larger number of the deep-sea corals of this region are found on 

 the rocky bottom extending along the coast of Cuba and outside the 

 Florida reefs, comparatively few being found in the Globigerina ooze of 

 the greater depths of the gulf and of the Florida straits. I have had 

 occasion before to remark on some differences in the distribution on the 

 two sides. As the coral fauna of the extremity of the Florida peninsula 

 is a colony of the "West-Indian, of comparatively recent origin, it is not 

 surprising that some forms have not borne the transportation, or failed to 

 propagate in the new habitat for some cause or other. I foel tolerably 

 certain of it in the case of Pentacrimis, the presence of which in a region 

 is so generally revealed by the numerous joints of the stem found in the 

 debris of the bottom. It is more difficult to account for the absence or 

 rarity on the coast of Cuba of forms very abundant on the Florida side. 

 Tlius Mr. Agassiz obtained but few specimens of Terehratula ciibensis and 

 Waldheimia floi-idana, which were almost a nuisance in my dredge on the 

 Florida coast. The same remark will apply to Balanophyllia fioridana, 

 Thecopsammia tintin?iabulum, Rhizotrochus fragilis, Distichopora foliacea, 

 AUopora miniacea, and a few others rare in Cuban waters, common on 

 the other side. 



It is to be regretted that no additional specimen of the singular 

 Haplophyllia paradoxa was obtained ; there is not even a fragment that 

 can be referred to it. 



