XARRATIVE OF THE CRUISE. 303 



and Badiolarian remains, and 25 per cent, of minerals and argillaceous matter. 



There were a few rounded quartz particles in each of the deposits, but the great majority 

 of the mineral particles were of volcanic origin. The carbonate of lime in these deposits 

 c( insisted chiefly of Globigerinas and Coccoliths. Neither Orbulinas nor Rhabdoliths were 

 observed in the deposits, nor at the surface, so that these Stations are probably beyond 

 the southern limit of these organisms. 



Dr. P. H. Carpenter and Professor L. v. Graff, of Graz, refer to some of the Crinoidea 

 and Myzostomida, found at these Stations, in the following summaries of their Reports 

 on these groups 1 : — 



The Crinoidea. — " Twelve genera of recent Crinoids are now known to science, six of 

 which are usually classed as ' Stalked Crinoids,' while the other six belong to the group of 

 Feather-stars, or Comatulse. Species of every genus, with the exception of Holopus 

 (see p. 153), were obtained by the Challenger, while the number of existing genera was 

 increased by one half, four being added to the eight previously known. The most 

 familiar of these is the beautiful Pentacrinus, a type closely allied to the well-known 

 Liassic fossils Extracrinus briareus and Extracrinus subangularis, specimens of which 

 have been found with stems from 50 to 70 feet in length. There are several 

 Jurassic and Cretaceous species of Pentacrinus, but only eight living ones are known. 

 Four of these have not been met with out of the Caribbean Sea, while two inhabit the 

 Atlantic and two the Pacific. The surveys of the U.S.C.S. steamer 'Blake' have discovered 

 Pentacrinus in depths as shallow as 42 fathoms, while it was found to be remarkably 

 abundant in 175 fathoms off Havana, one haul of the dredge and its appendages bringing 

 up no less than 120 individuals. There would seem, therefore, to be regular forests of 

 them upon the sea bottom in this and other localities, just as must have been the case in 

 the Liassie seas. Although Pentacrinus was only once met with in the Caribbean Sea at a 

 greater depth than 500 fathoms, both the Pacific species were obtained by the Challenger 

 between 500 and G30 fathoms, one of them possibly coming from 1350 fathoms. Failing 

 this last, Pentacrinus wyville thomsoni, which was dredged by the 'Porcupine' (1870) 

 off the coast of Portugal in 1095 fathoms, is the deepest Pentacrinus known. 



" The stem of this genus bears whorls of cirri which may be some distance (forty joints) 

 apart, as in Pentacrinus wyville thomsoni (fig. 117), or very close together, as in the Penta- 

 crinus maclearanus (fig. 116) from Station 122 (350 fathoms). The union of the nodal or 

 cirrus-bearing stem-joints with those beneath them is slightly different from that found 

 in the other parts of the stem, and is more easily severed ; and although individuals have 

 sometimes been found with their stems attached to telegraph cables by a slightly 

 spreading base, yet in other cases the stem appears to be free, having broken across 

 below one of the nodal joints, which becomes rounded off and closed up by a subsequent 



1 Report on the Crinoidea, by P. H. Carpenter, D.Sc, Zool. Chall. Exp., part xxxii., 1884 ; Report on the Myzos- 

 tomida, by Dr. L. von Graff, Zool. Chall. Exp., part xxvii., 1884. 



