388 



THE VOYAGE OF H.M.S. CHALLENGER. 

 Analysis of the above List. 



It thus appears that (1) the cruises of the " Porcupme " in 1869-70 added one genus 

 and three species to the three genera and five species previously known. (2) More tlian 

 half of the number (thirty-two) of knowTi species, including two new genera, were discovered 

 liy the Challenger. (3) More than 65 per cent, of the known species have been dis- 

 covered by H.M.SS. "Porcupine" and Challenger; while the small number of genera 

 known before 1869 has been doubled by the explorations of these two ships. 



BATHYMETRICAL TABLES. 



A Roman numeral opposite the name of a species shows that it also occurs in one 

 of the other Tables. 



Table I. — Species found at depths down to 100 fathoms. 



Pentacrinus milllen, II., III., IV. 

 Metacrinus interruptus. 



rotundus. 

 Metacrinus sp. (Vega). 



Holopus rangi, II. 



Rhizocrinus lofotensis, II., III., IV. V., VI.(?) 



rawsoni, II., III., V., VI. 

 Pentacrinus asterius,^ II., III. 



decorus, II., III., IV. 



^ Dredged by the "Lightning" in 1868, if not by the "Porcupine" in 1869. See Proc. Roy. Soc. Edin., vol. xii. 

 p. 356, 1884. 



- Two specimens in the Bristol Museum are believed to have been taken at a depth of 50 to 80 fathoms (Austin) ; 

 and the earliest known examples must certainly have been obtained at depths above 100 fathoms. 



