198 MR. P. H. CARPENTER OK THE GENUS SOLANOCRINUS 



d'Orbigny's original species and from that just described. The 

 distal faces of the radials have a very steep slope (PL IX 

 fig. 7S), so as not to enter very largely into the ventral aspect 

 of the calyx (fig. 7 a). The centrodorsal is a thick disk, the 

 sides of which bear several vertical rows of two, or occasionally 

 of three sockets each ; but there are none at all on the penta- 

 gonal dorsal surface, which is nearly flat. 



Diameter 8| millims. Height 5| millims. ; of radials 3 millims. 



I believe this species to be an Actinometra, and propose to call 

 it Act. wurtemlergica . Although the centrodorsal is relatively 

 thicker than it usually is in this genus, it is scarcely more so than 

 in the recent Act. stelligera (PL XII. fig. 26), while its dorsal 

 surface is entirely free from cirrhi as in the typical forms of the 

 genus. The proportions of the articular faces of the radials, their 

 steepness, and the consequent width of the central funnel are 

 also characteristic of Actinometra. They are not quite as steep 

 as in Act. lineata from Bahia (PL XII. fig. 27 a), in which the 

 calyx is remarkably " wall-sided;" but the same is the case with 

 one or two recent species, which are nevertheless undoubted 

 Actinometrce . 



As with most Jurassic Comatulce, the boundary between the 

 ligamentous and muscular fossae seems to have been very slightly 

 marked and to have become altogether lost. This feature, which 

 always indicates the small size of the muscular fossae, together 

 with the relative lowness of the articular faces, is very character- 

 istic of recent Actinometrce (PL XII. fig. 26) ; and it is very rare 

 in the recent species of Antedon. Almost the only one in which 

 it appears is Ant. rnacrocnema, from Sydney Harbour, which in 

 this, as in other respects, presents so many points of resemblance 

 to the Jurassic Comatulce. The majority of Cretaceous and recent 

 Antedons are of a type like that of Ant. antarctica (PL XII. 

 fig. 29 a), with high articular faces and large well-marked muscle- 

 fossae, which are separated from the ligament-fossae by a distinct 

 ridge. It is therefore interesting to find most of the earlier 

 Antedons approaching Actinometra in this respect. There are 

 however, a few exceptions. Thus, in Ant. Tessoni (PL X. fig. 10), 

 Ant. decameros (fig. 11), and Ant. scroliculata (figs. 17 a, 18 a) 

 the boundary ridge between the ligamentous and muscular 

 fossae is distinctly visible. De Loriol * has figured it in this last 

 species (pi. xx. figs. 11 b, 12 &), and also in Ant. Gresslyi 

 * ' Swiss Fossil Crinoicls,' loo. ait 



