674 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



additional was learned in regard to this genus until 1907, when Pro- 

 fessor Doderlein published his report on the- stalked crinoids of the 

 Sihoga expedition. In this he includes two new species, one obtained 

 by the German steamer Valdivia off east Africa, the other by the 

 Siboga in the East Indies. The latter,^, weberi, is possibly the 

 species recorded by Korotneff in 1886. 



Doctor Carpenter considered both Rhizocrinus lofotensis and R. 

 rawsoni extremely variable in all their characters, and so broad are 

 the diagnoses he gives that there appear to be no hard and fast lines 

 of division between them. This, taken in connection Avith the enor- 

 mous geographic and bathymetric ranges of the two forms as under- 

 stood by him, led me to believe that each of Carpenter's species was 

 in reality a composite of several. This opinion was confirmed by an 

 examination of several hundred specimens from the West Indies and 

 Gulf of Mexico in the United States National Museum and in the 

 Museum of Comparative Zoology at Cambridge. 



Rhizocrinus lofotensis does not occur on the American side of the 

 Atlantic, its place being taken, from Cape Cod to Florida, by R. ver- 

 rilli, which differs in being somewhat larger, generally stouter, with 

 a less expanded basal cone and much shorter columnars. 



RHIZOCRINUS CONIFER, new species. 



Basals separated b}'^ distinct sutures; calyx very long, conical, ex- 

 panding evenly from the top of the stem, the diameter at the distal 

 end of the radials about three times that at the distal (lower) end of 

 the basals; length of the calyx six times the distal diameter of the 

 basals and over twice the distal diameter of the radials ; a more or less 

 marked constriction at the level of the base or the middle of the 

 radials. The length of the calyx from the top of the stem to the end 

 of the radials is 11 mm. 



Stem moderately stout, probably about 150 mm. long; in the type 

 80 mm. long to the end of the thirtieth columnar; first columnar very 

 short and discoidal, second about four times as broad as long, third 

 not quite twice as broad as long, fourth about one-third longer than 

 broad, fifth about twice as long as broad, after the seventh or eighth 

 becoming three times as long as broad; second to fourteenth or 

 fifteenth slightly barrel shaped, then becoming more cylindrical, with 

 very slightly swollen ends. The longest columnars are about 3 mm. 

 long by 1 mm. in diameter. 



The first brachials are trapezoidal, longer than their proximal 

 width. 



Type-specimen.— Cat No. 22GT9, U.S.N.M.; from Albatross station 

 No. 2756; off Ceani, Brazil; lat. 3° 22' 00" S., long. 37° 49' 00" W.; 

 417 fathoms; bottom temperature, 40.5° F, 



