NOTES OX PALEOZOIC CRUSTACEANS 97 



seen elsewhere on these bodies; and, as this has about the 

 proper form and size for a rostral plate we are probably correct 

 in assuming that to have been its' office. 



AMomen and telson. Among all these specimens only a few 

 parts of the abdomen have been seen, and in but one of these in^ 

 stances are the parts in any way complete. This specimen has 

 the flexible posterior parts of the body turned forward and under 

 the carapace. The segments exposed appear to be five in num- 

 l)er, at first broad and short, becoming long and narrow back- 

 ward. The latter are furrowed medially on the under surface and 

 perhaps broadly ridged on the upper. The telson and cercopods 

 appear to be short and simple but have not been clearly dis- 

 played. The ornament on these parts is a strongly marked lat- 

 tice work or fish netting, notably coarse in proportion to the size 

 of the segments and making a very striking feature. While it 

 at once suggests the angular scale-like ornament on the seg- 

 ments of certain other ceratiocarids (C. s t y g i a, C. p a p i 1 i o) 

 it differs therefrom in forming elevated lines where the edges of 

 such scales would be. 



Remarks. The number of specimens observed of this species 

 shows it to have been not uncommon in the fauna of the Salina 

 black shale. The species is clearly a ceratiocarid, as evinced 

 by the absence of any trace of intercalary hinge plate (Rhino- 

 c a r i s) and in the character of ornament. Its numerous surface 

 ridges give it an aspect undeniably suggestive of the genus 

 Tropidocaris of the middle and upper Devonic, but its 

 relationships are evidently much closer to species of E m m e 1 - 

 ezoe and specially toE. crassistriata J. and W.^ So 

 far as now known this genus has been observed only at this 

 Tipper Siluric horizon, 



Z^^3 SOME DEVONIC PHYLLOCARIDA FROM NEW YORK 



PLATE 4 



Recent field investigations in the Ithaca strata of central 

 New 'York have revealed the somewhat widespread presence of 

 these interesting crustaceans. While none of markedly novel 



*Aii. and mag. nat. hist. 1849. 4:70, pi. 8, fig. 3. 



