204 ECHINODERMATA—ASTEROZOA SUB-BRANCH II 
Sub-Order 3. EUOPHIUREAE. 
Arms with dorsal, lateral, and ventral shields. Mouth shields well developed, 
one of them serving as a madreporite. Devonian to Recent. 

Fic. 330. 
Aspidura loricata, Goldf. sp. Muschelkalk ; Waschbach, Wurtemberg. A, Group of individuals of the 
natural size (after Quenstedt). B, Ventral aspect enlarged (after Pohlig). 
The Ophiuroids of the Mesozoic 
era are closely related to recent forms, 
B and are all assignable to families now 
in existence. Most of them have but 
two bursal fissures in each interradium ; 
but the genus Ophiura, Lam. (Ophio- 
derma, M. and T.), has four in each 
interray, and is represented as early 
as the Trias (0. Hauchecorni, Eck ; 
Muschelkalk. O. Egertoni, Brod. sp. ; . 
Lias). 
Fi, 331, The genera Aspidura (Fig. 330) 
opphinren Keliinene Bob. LithogephicSiates; and Aerura, Agassiz, are occasionally 
B, Dorsal surface of one of the arms. (Both figures abundant in the German Muschelkalk, 
enlarged ; original in Munich Museum.) e E . : . 
and certain Liassic Ophiurans also 


Pei 
YAM 

Fria. 382. 
Geocoma carinata, Goldf. Lithographic Slates; Zandt, near Solenhofen, Bavaria. 4, Individual of the 
natural size. , Dorsal aspect of disk, showing granulations and central depression. C, Ventral surface of one 
of the arms. (Figs. Band C enlarged.) ; 
lived in herds. In the Lower, Middle, and Upper Jura are found forerunners 
