254 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



that the type specimen of Antedon distincta in the Challenger collection resembles others 

 in the U. S. National Museum from the Philippine Islands. On the establishment of 

 the new genus Perissometra in 1916 selene was transferred to it. In my report on the 

 unstalked crinoids of the Siboga Expedition published in 1918 selene was included in 

 the key to the species of Perissometra and the synonymy and range were given; at the 

 same time distincta was included in the key to the species of Pachylometra, the range 

 and synonymy were given, and Charitometra smithi was included as a synonym under it. 

 In 1921 in a popular account of the recent crinoids I figured the side plates and the 

 side and covering plates of Pachylometra distincta. These figures were taken from Part 

 2 of the present work, figure 29 being a reproduction of figures 833 and 834, page 405, 

 and figures 30 and 3 1 being reproductions of figures 832 and 83 1 on the same page. 



After examining the type specimen of Antedon distincta Prof. Torsten Gislen 

 wrote in 1928 under Crossometra distincta that this species which I ranged in the genus 

 Pachylometra must be referred to Crossometra as it has the cirri arranged hi 10 columns 

 (or, as he gave it, rows). In 1934 Professor Gislen listed Perissometra selene among 

 the comatulids with the Comanthus solaster type of arm branching, and placed Pachylo- 

 metra distincta both among those species with the Perissometra macilenta type of arm 

 division, and among those with the Crosscmetra septentrionalis type of arm division. 



GLYPTOMETRA INVESTIGATORIS (A. H. Clark) 



PLATE 24, FIGURES 74, 75; PLATE 25, FIGURES 76-78 

 [See also vol. 1, pt. 2, figs. 226, p. 180, 537, 538, p. 289, 673, p. 335, 867, p. 419.] 



Pachylometra investigatoris A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 82 (description; 



Malay Archipelago; 30 fathoms); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 556 (compared with 



P. luna and P. selene); Crinoids of the Indian Ocean, 1912, p. 216 (synonymy; detailed descrip- 

 tion; locality), fig. 39, p. 217. 

 Pachylometra luna A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 556 (description; Albatross 



station 5325; comparisons); Crinoids of the Indian Ocean, 1912, p. 219 (synonymy; locality). 

 Pachylometra hetius A. H. CLARK, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 78 (description; 



Siboga station 254). 

 Crossometra helius A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 (listed); 



Unstalked crinoids of the Siboga-Exped., 1918, p. ix (relationship with C. septentrionalis), p. 



174 (in key; range), p. 175 (detailed description; references; station 254), p. 274 (listed), pi. 



24, fig. 67; Treubia, vol. 14, livr. 2, December 1933, p. 207 (previous records), p. 214 (Bali Sea; 



notes). GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 26. 

 Crossometra investigatoris A. H. CLARK, Journ. Washington Acad. Sci., vol. 6, No. 17, 1916, p. 606 



(listed); Unstalked crinoids of the Siboja-Exped., 1918, p. 174 (in key; range), p. 175 (references; 



notes; station 297), p. 275 (listed). GISLEN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, 



No. 11, 1934, p. 26. 



Diagnostic features. The cirri, which are arranged in 10 columns on the centro- 

 dorsal, have 20-31 (most commonly 22-27) segments, and are 25-47 (most commonly 

 30-35) mm. long; the proximal segments are longer than broad and the distal are about 

 as long as broad or slightly broader than long; the 18-32 (most commonly 26-30) arms 

 are 110-170 mm. long; and the division series and proximal brachials are smooth. 

 There seems to be little real difference between this species and G. distincta. 



Description.' The centrodorsal is a truncated cone 7 mm. broad at the base and 

 5 mm. high. The cirrus sockets are arranged in two columns of from 3 to 5 each in each 

 radial area, the two columns of each area being separated by a narrow median line not 



