246 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



In my first revision of the old genus Antedon published in 1907 Antedon inaequalis 

 was transferred to the new genus Charitometra, and in 1908 I compared Charitometra 

 inaequalis with a new species, Ch. smithi. On the establishment of the genus Pachylo- 

 metra in 1909 inaequalis was transferred to it. In my memoir on the crinoids of the 

 Indian Ocean published in 1912 Pachylometra inaequalis was listed and the range and 

 synonymy were given, and in 1913 I gave notes on the Challenger specimens I had 

 examined at the British Museum two from station 174, one from station 175, and 

 three from station 170. In 1918 in my report on the unstalked crinoids of the Siboga 

 Expedition inaequalis was included in the key to the species of Pachylometra and the 

 synonymy and range were given. In 1928 Prof. Torsten Gislen published additional 

 notes on the specimens in the British Museum, and in 1934 he listed Pachylometra 

 inaequalis among those comatulids with the Perissometra macilenta type of arm divi- 

 sion, and also among those with the Crossometra septentrionalis type of arm branching. 



GLYPTOMETEA SEPTENTRIONAUS (A. H. Clark) 



[See vol. 1, pt. 1, fig. 369, p. 299; pt. 2, fig. 675, p. 335.] 



Charitometra distincla A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 312 (Sagami Bay). 



Pachylometra septentrionalis A. H. CLARK, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 554 (description, 

 based upon the preceding); Proc. Biol. Soc. Washington, vol. 25, 1912, p. 78 (compared with 

 P. helius); Crinoids of the Indian Ocean, 1912, p. 215 (synonymy; locality); Journ. Washington 

 Acad. Sci., vol. 5, No. 6, 1915, p. 215 (southern Japanese species; range and its significance). 



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

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

 175 (in key; range), p. 176 (references). GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, 

 vol. 5, No. 6, 1922, p. 119 (Bock's station 36; notes), figs. 77,78, p. 88; Zool. Bidrag Uppsala, vol. 

 9, 1924, pp. 44, 71, 80, fig. 80, p. 81 (syzygial face) , fig. 109, p. 93 (synarthrial face) ; Kungl. Fysiogr. 

 Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 26. 



Crossometra distincta GISL&N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 120. 



Diagnostic jeatures. The proximal portion of the animal is very broad, the profile 

 of the division series and arm bases being strongly convex; the ossicles of the division 

 series and first two brachials each bear a more or less developed low rounded tubercle; 

 the distal cirrus segments are broader than long and bear dorsally a high narrow sharp 

 keel the crest of which is parallel to the longitudinal axes of the segments ; the 33 arms 

 are 130 mm. long; and the cirri have 19-23 segments. 



Description. The centrodorsal is very rounded conical, broader at the base than 

 high, with the bare polar area very small, 1 mm. in diameter, and surrounded by 5 small 

 radial tubercles. The cirrus sockets are arranged in 10 closely crowded columns of 

 2 or 3 each. 



The cirri are XX, 19-23, about 35 mm. long, very stout, and in lateral view in- 

 creasing considerably in width in the outer portion. The first segment is short, twice 

 as broad as long, and the following gradually increase in length to the fourth which is 

 about as long as broad. The succeeding segments are similar to the fourth, the terminal 

 becoming slightly broader than long. The penultimate segment is of less width than 

 those immediately preceding, and is half again as long as broad. On the fourth or 

 fifth segment the dorsal surface becomes rounded carinate, this carination slowly 

 becoming higher and sharper, on the distalmost 10 or 12 standing out as a high narrow 

 sharp keel the distal portion of the profile of the crest of which in lateral view is seen 



