384. -«R. P. Whitfield—New Forms of Fossil Crustaceans 
stated in the Illustrations of Devonian Fossils that one specimen 
resembling C. punctatus bas been found with a body similar to 
that called C. armatus attached to the carapace, showing their 
individual relations. 
he several species above mentioned, while eet a 
from Ceratiocaris, possess features in common which a 
characterizes them as a natural group, sitiscewite maken re 
be vrtech distinguished. I therefore propose to recognize them 
istinct genus under the eneeie name EcHINOCARIS, pos- 
eatng the following character: 
EcuINnocaRIis, new genus. 
Carapace bivalve, valves subovate in outline; united on the 
dorsal margin by a straight hinge; the anterior, basal and’ pos- 
terior margins rounded, and generally more or less produced 
posteriorly. Surface of the valves marke by a more or less 
dlistinetly elevated, curved, longitudinal ridge, centrally or 
subcentrally situated ; also by one or more (usually three) 
vertical ridges, or ridge-like nodes, extending downward from 
the hinge-line upon the body of the valve, and usually ana 
anterior to the middle of the length. Abdomen naked, com- 
posed of several segments (four known) and a caudal fans 
which is produced into an elongated spine with a lateral, mov- 
able spine on each side. Posterior margin of the abdominal 
segments bearing spines on the now known species. Type 
Echinocaris sublevis Whi 
bears to other known genera. 
1st section: Carapace more or less elongated, with a straight 
or slightly arched dorsal line; anterior end sharply rounded or 
pointed (rostrate); posterior end ih neate; sides convex, smoot! 
or simply striate, sometimes ma by a simple ocular node 
near the antero-dorsal margin; no ies or othee nodes. Cera- 
teocaris McCoy, 1849; Caryocaris Salter, 1862; Hymenocaris 
Salter, 1852 ; Solenovaris Meek, 1872 ;(?) Colpocuris Meek, 1872. 
The last somewhat questionable i in character. 
2d section: Carapace similar in form to that of section 1, 
with the postero-basal angles produced into spines, and the sur- 
con with longitudinal ridges. Dithyrocaris Scouler (=Argas 
i. 
ed section: Carapace rounded at both extremities, elongate- 
