October, 1913. New Trilobites — Slocom 61 



Order PROPARIA. 



Family ENCRINURID^, Linnarsson. 



Genus ENCRINURUS Emmrich 1844. 



"Cephalon tuberculate; glabella pyriform, prominent; free cheeks 

 narrow, separated in front by a small rostral plate; eyes small, elevated 

 on cOnical prominences; thoracic segments eleven; pygidium triangular, 

 numerous annulations on the axis; pleurae with few ribs." Range, 

 Ordovician and Silurian, Europe and America. {Zittel- Eastman Text 

 Book Pal., p. 634.) 



Vogdes* divided the above genus by placing all species without 

 genal spines in Cryptonytnus Eichwald, but his point does not appear to 

 be well taken for two reasons. (1) In 1825 Eichwald described the 

 genus Cryptonytnus with C. scholotheimi as genotype. Seven other 

 species were placed in the genus. The genotype and three others were 

 found to belong to the genus Asaphus Brong., the balance to Illcenus 

 Dahlman. In 1840 Eichwald again used the name Cryptonymus for a 

 genus entirely different from the one described, in 1825, thus using a 

 preoccupied name. (2) The presence or absence of genal spines does 

 not appear to the- writer to be of generic importance. 



Encrinurus pernodosus sp. nov. Plate XVI, Figs. 5-7. 



Type specimens Nos. P 17038 and P 16930 Field Museum. 



Body ovate in outline, trilobation distinct, without genal or caudal 

 spines. 



Cephalon sublunate in outline, anterior margin inflated, width more 

 than twice the length. Glabella subhemispherical, width somewhat less 

 than the length, slightly protruding beyond the anterior margin; three 

 pairs of indistinct lateral glabella furrows define the lateral lobes; these 

 furrows rapidly decrease in depth from the dorsal furrows and become 

 obsolete among the tubercles; a well-defined furrow originates on the 

 dorsal furrows about midway between the anterior lateral glabella 

 furrows and the anterior marginal furrow and bends slightly forward in 

 crossing the anterior lobe of the glabella; anterior glabella lobe large, 

 comprising nearly half the glabella, lateral lobes quadrangular, de- 

 creasing rapidly in size posteriorly; occipital segment narrow, resembling 

 the axial portion of one of the thoracic segments in size and form; 

 occipital furrow narrow, angular, well-defined; dorsal furrows deep, 

 angular, diverging somewhat from the occipital furrow to the anterior 



*Trans. San Diego Soc. Nat. Hist. Vol. I, No. 2, p. 74. 



