526 



BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Tlie great variability among the specimens called inusituta which I have examined 

 suggests that they are immature and do not represent a distinct species themselves. 



At Investigator station 13 and at Siboga stations 38 and 45 inusitata was associated 

 with mira. At Siboga stations 178, 314, and 316 inusitata was found alone. The 

 occurrence with mira suggests a relationship between the two, since nowhere are two 

 species of this, or of any of the related genera, ever found together. The occun-ence 

 alone at 3 stations very likely means that the larger individuals, which in most of the 

 Antedonidae are much more brittle than the young, were so fragmented that they were 

 not considered worth preserving. 



I can find no tangible differences between Gislen's Ps. wireni and this species as 

 represented by inusitata. 



PSATHVROMETKA MINIMA (A. H. Clark) 



Figure 26 



Psathyrometra minima A. H. Clark, Notes Leyden Mus., vol. 34, 1912, p. 141 (description; Siboga 

 sta. 48); Die Crinolden der Antarktis, 1915, p. 116 (range); Unstalked crinoids of the Siboga- 

 Exped., 1918, p. viii (discovery by the Siboga and its significance), p. 226 (in key; range), p. 228 

 (description; sta. 48), p. 271 (listed), pi. 26, fig. 91. 



Psathyrometra minimus A.H.Clark, Die Crinolden der Antarktis, 1915, p. 117 (comparison with Ps. 

 antarctica) . 



Diagnostic features. — The single known specimen has the centrodorsal 1.9 mm. in 

 basal diameter and 1.6 mm. in vertical height, with 4 or 5 cutus sockets in each radial 

 area in two irregular columns; interradially there is a flat or slightly grooved space 

 between the columns; the arms, cirri and pinnules are unknown. 



Description [bj' A.M.C.].- — The centrodorsal is conical with the sides fairly straight 



Figure 26.- 



-Psathyrometra minima A. H. 

 Clark, holotype. 



