NOTES OX PALEOZOIC CRUSTACEANS 103 



tion of antecedent to consequent. D i t h y r o c a r i s is a 

 Carbonic genus, and we may doubt its occurrence in any earlier 

 strata. The authors cited refer to but one species from the De- 

 vonian, D. belli Woodw. from Gasp6, but it is not possible 

 from the figure and description of that species to determine its 

 generic character. 



Eleutherocaris Clarke. In Eastman-ZittePs Textbook 

 of paleontology, p. 656, the generic term Eleutherocaris 

 was introduced by the writer, having for its type speciesr the 

 Ceratiocai-is whitfieldi Clarke, of the Naples shales 

 ■ of Naples (N. Y.). In the course of editing, this species 

 name was struck out of the text, leaving the genus standing 

 alone, a nomen nudum. The carapace of Eleutherocaris 

 whitfieldi differs notably from that of Rhinoca.ris in 

 the broad, low nodes of the cephalic region and in its very short, 

 oblique anterior lateral carina. Its cephalic nodes are more 

 nearly comparable to those of E c h i n o c a r i s, with which 

 genus the species was associated in vol. 7, Paleontology of Neio 

 York. The truncate extremities, both anterior and posterior, 

 have not been observed in Rhino car is or in Echino- 

 caris. The hinge line in this species seems to be long and 

 straight with an anterior cleft for a rostrum, but no satisfactory 

 evidence is present of an intermediary dorsal plate. 



4 THE OCCURRENCE OF THE PHYLLOPOD CRUSTACEAN 

 ESTHERIA MEMBRANACEA OF THE OLD RED SANDSTONE OF 

 NORTHERN SCOTLAND AND NORTHWESTERN RUSSIA, IN THE 

 ONEONTA-CATSKILL SEDIMENTS OF EASTERN NEW YORK 



PLATE 4, FIGURES 1-4 



Estheria membranacea is one of the longest and most 

 widely known of the fossil phyllopods. It has been generally 

 regarded as a characteristic accompaniment of " Old Red " sedi- 

 mentation both in northern Scotland and in Livonian Russia. 

 At the time Prof. T. Rupert Jones issued his well-known 

 Monograph of the fossil Estheriae^ the occurrences of the species 



^Paleontogr. soc. vol. for 1860 (1862). 



