GEOGRAnilCAL DISTRIBUTION. 



We are as yet too little acquainted with the deep-sea fauna of other 

 parts of the world to be able to trace the distribution of our corals. 

 The only parts of the sea bottom well exj)lored up to the present time, 

 besides the Florida Straits, are along the coasts of Europe from Norway 

 to the Straits of Gibraltar and the Mediterranean. The comparison of 

 the Echinoderms of the tAvo regions has revealed quite a number of 

 species common to both (see Bull. Mus. Com. Zool., Nos. 9 to 12). 

 But this is not the case with the corals ; Dr. P. M. Duncan, in his paper 

 on the Madreporaria dredged up in the expedition of H. M. S. " Porcu- 

 pine," enumerates four species common to the northern seas of Europe 

 and the Florida Straits, namely, DiploheUa profunda, Lopholielia prolifera^ 

 Thecopsammia socialis and PUobothrus sfptimetricus. Lopholielia prolifera is 

 found also in the Mediterranean. To these can be added CaryopUijllia 

 claims, which has about the same range as the last. Madracis asperula 

 and Cladocora debUis are found in Florida and Madeira, but they cannot 

 properly be called deep-sea corals. 



The observations on the coast of Cuba are so few, that no definitive 

 conclusions can be drawn as to the difterences between the faunae of the 

 two sides of the straits, but I have found no reason yet for doubting 

 the statement made in a former paper, that certain species are found 

 only on the Cuban side ; for instance, Sti/lastcr complanatm, Dldichopora 

 mdcaUi, Errina carinata, Lepidopora (jlahra, Deudroph/jllia cyathoides, and 

 Pliohothnis iubidatns. Examples from other classes can also be found, 

 which appear never to have crossed the Gulf Stream and the straits : 

 such is the Pentacrinus. 



