264 HAWAIIAN AND OTHER PACIFIC ECHINI. 



recorded in the Revision from the Florida Gulf Stream, off Tennessee Reef, 

 and Charleston, S. C, and it is indicated that specimens from those localities 

 are in the M. C. Z. collection. The only American specimen of flavescens now 

 in the M. C. Z. collection is a bare, broken test, about 38 mm. long, from Folly 

 Island, Charleston, S. C. So far as can be judged from its present condition, 

 it is certainly flavescens. I think therefore that the species is properly recorded 

 from the American coast. 



Echinocardium laevigaster. 



A. Agassiz, 1869. Bull. M. C. Z., 1, p. 277. 



In the Revision, Mr. Agassiz united this species with pennatiftdum but 

 Mortensen has suggested that it is probably distinct. The material at hand 

 consists only of the holotype from "Florida. Pourtales coll." ' and a fragment 

 of an adult specimen from "off Tennessee Reef, Fla., 114 fms. Pourtales coll." 

 The holotype is more or less bare and is now partly broken but there is no doubt 

 that it is the original of figs. 1 and 2, plate xx of the Revision, which are there 

 labeled pennatifidum. Neither on it, nor on the fragment, have I found any 

 pedicellariae save some small tridentate which are not at all distinctive. They are 

 much like Mortensen's fig. 44, pi. 17 (1907. Ingolf Ech., pt. 2) but the valves 

 are less curved, the whole head being quite pyramidal. In the holotype, three 

 plates with two large pore-pairs enter into each side of the subanal plastron. 

 The periproct is a little wider than long but the plastron is rather longer than 

 wide. The peristome is 8 mm. wide and 4 mm. long. The labrum is rather 

 long, reaching the middle of the second ambulacral plate. There are many 

 primary tubercles above the ambitus in interambulacra 2 and 3, and there 

 seem to be one or two near the anterior edge of interambulacra 1 and 4. The 

 area enclosed by the internal fasciole is 12 mm. long, just one third of the test 

 length. The anterior petals are fully 12 mm. long with 10 pore-pairs in the 

 posterior series, while the posterior petals are little more than 10 mm. long, and 

 have only 7 pore-pairs in the posterior (inner) series. It is evident that this 

 species is not very near pennatifidum but it is very near morte7iseni and dubiutn. 

 Further material will undoubtedly differentiate the three species more clearly, 

 as they seem to be quite distinct. 



1 Mr. Agassiz gives the depths as 79-121 fms 



