Narrative of Bahama Expedition. 173 



able individuals of certain species, apparently to the exclusion 

 of others. This was particularly noticeable in the case of 

 Dorocidaris fapillata A. A<^., which repeatedly came up on 

 the tanplcs by the hundred, and became a sore trial to our 

 patience, the serrated spines being especially diiVicult to disen- 

 gage from the tangles. Indeed, this labor became one of our 

 main occupations while on the Pourtales Plateau. Dorocidaris 

 harfktti A. Ag. is a beautiful species with the spines banded 

 with red and white. Dororidcrn's blakei A. Ag. is regarded 

 by its describer as "perhaps the most interesting of the recent 

 Cidarid.-e.'' All of our specimens, unfortunately, were with- 

 out the peculiar fan-shaped spines or radioles which consti- 

 tute the most striking peculiarity of the species. The char- 

 acters of the test were well marked, however. Cidaris trihii- 

 loidcs Bl. was also secured. 



Coelofleiinis ^hn'dcDiiis A. Ag. was probably the most beau- 

 tiful of the true sea-urchins collected at this time, some speci- 

 mens being considerably larger than those secured off Havana. 

 Not only are the long, slender spines brilliantly colored with 

 carmine and white or orange, but the test itself is equally 

 striking w ith its alternate chocolate and orange zones, making- 

 it resemble the gorgeously colored balls in which children 

 delight. The largest sea-urchin secured during the entire 

 cruise came from a depth of one hundred and five fathoms. 

 This was a huge specimen of Ast/iciiou>iiiii /lystn'.x A. Ag.. a 

 representative of an ancient group of I'^chini, with flexible 

 tests and overlapping coronal plates. This specimen was 

 seven inches across the test, and was swollen out, when it 

 came on deck, to the regulation outline for a sea-urchin, 

 although Agassiz sa\s that the e hallenger specimens in alco- 

 hol were --as flat as pocket handkerchiefs, and were naturally 

 regarded as flat sea-urchins, although, of course, endowed with 

 great mobility of test.''^ Our specimen gave us a good idea 

 of the temperature of the bottom, for it was inflated with 

 water which had not yet been warmed by the surface heat, 

 and felt icy cold to the hands. We soon discovered, however^ 



J" Three Cruises of tlic 'lilake,"" \'ol. II, ]t. 94. 



