ie, ECHINODERMATA—PELMATOZOA SUB-KINGDOM III 
on the ventral. Tegmen unknown. Upper Jura; a rare form, found in the 
Franconian and Swabian Alp. 
Hyocrinus, Wyv. Thomson (Fig. 288). This recent form is obviously 
allied to the preceding, but differs from it rather conspicuously in the mode 
of branching of its arms. It has a heavily plated tegmen, with mouth sur- 
rounded by large orals. Carpenter regards it as the type of an independent 
family. 
Family 7. Saccocomidae. d’Orbigny. 
Yulyx small, hemispherical, non-pedunculate. Radials five, very thin, elevated 
into prominent ridges along the median line, and enclosing an extremely small basal 

Fic. 289. 
Saccocoma pectinata, Goldf. Upper Jura (Lithographic Slates); Eichstadt, Bavaria. «, Individual in natural 
size ; b, Side view of calyx; c, Calyx seen from below, 2/;; d, Two of the lower arm-plates ; e, Two arm-plates of 
a higher order with one of the branches; jf, The upper part of one of the arms straightened out; g, Lower 
brachials of S. tenella, Goldf. (Figs. d and g greatly, the others slightly enlarged.) 
plate. Arms 5x2; thin, widely separated, and giving off alternately towards the 
extremities simple incurving branches. Arm-plates cylindrical ; each side of the 
ambulacral furrow lined with wing-like or spiniform projections. The entire skeleton 
exhibiting a reticulated structure with coarse meshes. Upper Jura. 
The only known genus, Saccocoma, Ag. (Fig. 289), occurs profusely in the 
Lithographic Slates of Eichstiidt and Solenhofen, Bavaria. It is a free- 
swimming form, whose affinities with the monocyclic Plicatocrinidae were first 
clearly demonstrated by Jaekel.! 
1 Zeitschrift der deutschen geol. Gesellsch. Bd. XLIV., 1892. 
