Narrative of Bahama Expedition. 83 



It seems to me that such striking coloration in regular 

 pattern as is often found among the deep-sea echinoderms is 

 good presumptive evidence that there is a considerable quan- 

 tit}- of light at the sea bottom, whether the illumination comes 

 from the upper world or is furnished entirely by the various 

 phosphorescent animals. 



Ccrlop/ciinis floridai/u^, a beaulifull}" colored species allied to 

 the Arbacca of our coasts, made a pleasing disphi}' with its 

 brilliant crimson and white spines. The four triangular anal 

 plates of this species is usually given as a family character of 

 the Arbacrid.^. but among our specimens of Ctvloplcnnis 

 foridainis was one with three plates, others with four, and 

 one with hve. In examining the series it so happened that 

 the writer found the three in the order named, nuich to his 

 astonishment. Salcnia pattersoiii, another species with spines 

 banded with vermilion and white, is rendered still more at- 

 tractive bv bands of deep violet following the ambulacral 

 furrows, and outlining the plates of the apical system, the 

 ground color being a dove or cream color. The anal opening 

 is quite eccentric in this sea-urchin, and Alexander Agassiz 

 thinks that the suranal plate is the homologue of the centro- 

 dorsal of star-fishes and crinoids. A beautiful specimen of 

 Asfiidodiadeina may represent a new species, the spines being 

 ringed with rich purplish violet and white in striking contrast. 



Some small specimens of Echini probably belonging to the 

 genus Teniiiccliimis were secured, and also a few small Petal- 

 osticha which have not 3'et been identified. 



The coelenterates of the pentacrinus ground are little less 

 interesting than the echinoderms. The assemblage of forms 

 belonging to this subkingdom embraced almost nothing that is 

 familiar to the naturalist whose work has been confined to 

 sliallow water. 



The corals are almost all of the simple old-fashioned t\pe. 

 not one of the familiar West Indian reef-builders being found 

 at this station. Pourtales, who had the honor of first calling 

 the attention of the scientific world to the deep-sea corals of 

 the Gulf Stream, says. '• The total of sixty-four species is 



