SYNOPSIS OF GENERA. 
Ixi 
abundant cephalopod and furnishes the only instance observed, after the most 
careful examination of the rocks, of any such association of these bodies, and 
also the only example of the occurrence of a body resembling Dipterocaris in 
these beds. If this association is not purely accidental, and if there actually 
existed any organic connection between the Goniatite and the enclosed body, 
the latter has certainly not been similar in function to the aptychi. 
While it is necessary to recognize the fact that of the bodies included under 
the genera Spathiocaris, Cardiocaris, Discinocaris, Dipterocaris, Pterocaris and 
Pholadocaris some are undoubtedly crustacean and others, with certainty, 
cephalopodous, with our present knowledge it is impossible to draw the divid¬ 
ing line between them. 
ORDER, DECAPO DA. 
Family, CARiDiDiE. 
Genus PAL OPAL /E MON, Whitfield. 1880. 
Diagnosis. Cephalothorax not rostrate (?), keeled upon the dorsum and sides. 
Antennules not observed. Antennae with very strong basal joints, exceeding- 
in strength any of the thoracic appendages. Eye-peduncles probably short. 
Thoracic ambulatory appendages slender, not forcipate. Abdomen composed of 
six segments. Telson short, rapidly tapering and connected by a membranous 
expansion with the lateral caudal spines. In the midst of this caudal expansion 
lies a pair of thin lamellar spines articulated at their proximal extremities to 
both telson and lateral spines. 
ORDER, PHYLLOPODA. 
Family, LiMNADiADAi. 
Genus ESTHERIA, Ruppell. 
(DEVONIAN SPECIES ONLY.) 
1846. Posidolwmya, Eichvvald. Geol. Russia. 
1849. Asmusia, Pacht. Devon. Kalk in Livland. 
