A MONOGRAPH OF THE EXISTING CRINOIDS 393 



Bathymetrical range.— From 100 to 195 (?254) meters; the average of 6 records is 

 181 meters. 



Thermal range.— From 11.61° C. to 15.89° C; the average of 5 records is 13.47° C. 



Remarks. — The confusion in regard to this species was due to the occurrence on 

 the specimen described as the type of caUisia of only a single cirrus which is unusually 

 slender and has the earlier segments unusually long. At the time, in the absence of 

 any other indications, this cirrus w'as considered as representing the cii-ri of the 

 species as a whole. The ch-ri of the specimens included under the name separata 

 resembled closely those of Neometra multicolor and were therefore very different 

 from the single cirrus remaining on the type of callista. The true allocation of 

 separata proved to be a matter of no little difficulty. In my first division of the genus 

 Calometra in 1912 separata was assigned to the new genus Pectinometra. But it 

 soon became evident that it could not remain here, and in 1915 I reassigned it to 

 Calometra, restricted, considering it to differ from C. callista in having much shorter 

 cirrus segments. On looldng into the question again, however, I fomid on the type 

 of separata a curious elongate unusually slender cirrus with very long earUer segments 

 exactly resembling the only cirrus on the type of callista, so that now I have no hesi- 

 tation in pronouncing the 2 supposed species to be in reality identical. 



The association of this species with the other two species of the family occurrmg 

 on the southern coast of Japan, Neometra multicolor and Pectinometra flavopurpurea, 

 is discussed on page 383. 



Family PTILOMETRIDAE Gisl^n 



Spinifera group (in part) P. H. Carpenter, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, 

 p. 211 {Antedon macronema only); for further references see part 4c. 



Thalassoiuetridae (in part) A. H. Clark, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 136; for 

 further references see part 4c. 



Thalassometrinae (in part) A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 2; for further 

 references see part 4c. 



Thalassomfetres (in part) A. H. Clark, Bull. Mus. Hist. Nat., Paris, No. 4, 1911, p. 255. 



Ptilometrinae A. H. Clark, Bull. Inst. Oc6anogr. Monaco, No. 294, 1914, pp. 7, 8 (temperature 

 relations); Journ. Washington Acad. Sci., vol. 4, No. 19, 1914, pp. 559-563 (correlation of 

 geographical and bathymetrical ranges); No. 20, 1914, p. 582 (relation to temperature of 

 habitat); vol. 5, No. 4, 1915, pp. 120-134 (bathymetrical range and its significance); Die 

 Crinoiden der Antarktis, 1915, p. 132 (covering plates); Amer. Journ. Sci., vol. 40, 1915, p. 67 

 (detailed discussion of bathymetrical range); Smithsonian Misc. Coll., vol. 65, No. 10, 1915, 

 p. 41 and following (phylogenetic study); L'nstalked crinoids of the Siboga Exped., 1918, p. 139 

 (in key; geographical and bathymetrical ranges), p. 140 (key to the included genera); Smith- 

 sonian Misc. Coll., vol. 72, No. 7, 1921, p. 3.— GisLfiN, Zool. Bidrag Uppsala, vol. 9, 1924, 

 pp. 85, 90.— A. H. Clark, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, 1929, p. 647; Treubia, 

 vol. 14, livr. 2, 1933, p. 213. 



Thalassometndeu (in parti A. H. Clark, Die Crinoiden der .\ntarktis, 1915, p. 192. 



Ptilometridae Gisl£n, Kungl. Fysiogr. S&Usk. Handl., new ser., vol. 45, No. 11, 1934, pp. 18, 20, 

 25.— A. H. Clark, John Murray Exped. 1933-34, Sci. Reports, vol. 4, No. 4, 1936, p. 103.— 

 H. L. Clark, Echinoderm fauna of Australia, 1946, p. 23 (in key), p. 55. 



Diagnosis. — A family of the superfamily Tropionietrida in which the ventral 

 perisome of the pinnules is protected by fairly well-developed side- and covering- 

 plates; Pi resembles Pj but is shorter and more slender; the muscular fossae on the 

 radial articular faces, in sharp contrast to those of the Asterometridae and Thalasso- 



724008 — 47 26 



