80 T. GisLÉN, 



propoi'iion to ilio length of the aims. A distinguishing chai'actei-islic 

 of vahie inigiit also be the clislrihiilioii of the syzygies. In C. tlii^ci- 

 formis the syzygies are separated by 15 to 4, in G. manea by 9 to 10 

 oblique articulations. This difference is also to be found in the oi'i- 

 ginal descriptions, where the first-mentioned species is said io liave 

 syzygies with a syzygial interval of 2 — 6, the latter with an interval 

 of 4 — 10 (usually 7 — S) joints. Tlic preceding species also seems to 

 be more slender and to have longer and nai'i'ower distal pinnules 

 than the one described below. 



It might be worth while to call attention to the fact thai the 

 genus Ci/Uomelra., as also many other Colohomelrids, approaches in 

 many respects the Ante.donid subfam. Perometrince. Both groups have 

 an inconstant P.,. The Coloboinetrids, being an Oligojyhreat family, have 

 unusually long pinnulars and cirrals, where the first-mentioned ones 

 especiallj' are very similar to those of the Antedonidœ. Perometrina', 

 on the other hand, being a Macrophreat family, has short cirrals 

 and pinnulars. The basal rays are often absent in the Golobometridœ 

 and the rosette ' very similar to that of the Macrophreais. Also the 

 eentrodorsal cavity is unusually large. A feature distinguishing Go- 

 lobometridœ from PerometrinfP is the occurrence of a double spine-row 

 or a transverse crista on the proximal cirrals. On the distal segments, 

 however, the dorsal spine is single. If a reduction of the spines of 

 the proximals cirrals took place, we might probably refer a Golobo- 

 metrid to Perometrinœ. It seems therefore as if we should find con- 

 nections between Golobometridœ and Perometrinœ ; the latter is possibly 

 in this case to be deduced from the former and has developed con- 

 vergently with the Aniedonid typus (cf. p. 80 ff.). 



Cyllometra manca (P. H. Caiîp.). 



Fig. (iO, 07. 



Syn.: Antedon manca 1888 P. H. C.\rpenteu Cliall. Exp. Vol. 26, p. 226. 



Cyllometra manca 1907 A. H. Cl.aek Smiths Misc. Coll. Vol. 50, p. 357; 

 1912 Grin. Ind. Oc, p. 156; 1913 Smiths. Misc. Coll. Vol. 61: 15, p. 34; 1915 Mo- 

 nograph p. 89, 374; 1918 Siboga Exp. Vol. 42 B, p. 116. 



From St. JO: 1 specimen. 



Sp. 1 Cd large, discoidal, free dorsal pole 2,8 mm. C. XXIII 23 

 — 25; 10—11 mm. in two whorls. All segments are shorter than long. 



