388 THE VOYAGE OF H.M.S. CHALLENGER. 
Analysis of the above List. 
“ Poreupine.” Challenger. “ Blake.” 
Number of 
Gene ae Now Species Nine Species Nee Species 
Species. | PEVOUSY | Species, | PVIOUSY | Species. | Previously 
Holopus, : : 1 tye ae ie a ete 1 
Hyocrinus, . ; 1 Yes Br 1 | 
Bathycrinus, . : 4 1 2 
Rhizocrinus, . 2 1 11 2 2 | 
Pentacrinus, . : 9 | 1 ie 4 208 1 3 
Metacrinus, . : 15 s a 11 a zs wee | 
Total known species, 32 3 1 18 2 1 6 
It thus appears that (1) the cruises of the “ Porcupine” in 1869-70 added one genus 
and three species to the three genera and five species previously known. (2) More than 
half of the number (thirty-two) of known species, including two new genera, were discovered 
by 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. 
TasLE I.—Species found at depths down to 100 fathoms. 
Holopus rangi, I. | Pentacrinus miilleri, I1., I1I., TV. 
Rhizocrinus lofotensis, IT., I11., IV. V., VI.(?) | Metacrinus interruptus. 
rawsoni, IL, IIL., V., VI rotundus. 
Pentacrinus asterius,” 11., 111. Metacrinus sp. (Vega). 
decorus, II., III, IV. : 
1 Dredged by the “Lightning” in 1868, if not by the “Porcupine” in 1869. See Proc. Roy. Soc. Edin., vol. xii. 
p. 356, 1884. 
2 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. 
