NO. 7 PTYCHOPARIID TRILOBITES — RASETTI 1 5 



the border ; marginal furrow regularly curved, except for a slight 

 median inbend appearing only in some individuals ; border convex, 

 tapering in width at the sides. Palpebral area slightly convex, on the 

 average horizontal, 0.7 times as wide as the glabella ; ocular ridges 

 well marked, slightly curved ; palpebral lobes slightly less than half 

 as long as the glabella, at the level of the glabellar midpoint, somewhat 

 elevated, set off by well-marked palpebral furrows. Posterior limbs 

 deeply furrowed, as wide (tr.) as the glabella; distal portion almost 

 as wide (tr.) as proximal portion. Anterior facial sutures slightly 

 divergent in front of eyes, curving inward after crossing marginal 

 furrow ; posterior branch turning backward in wide curve. Surface 

 of test very finely granulated. Length of largest cranidium 9 mm. 



Remarks, — The illustrations show the variability observed among 

 cranidia of this species (all recovered from the same boulder) in the 

 rate of tapering of the glabella and the presence of a more or less 

 definite inbend of the marginal furrow. The latter is usually more 

 apparent in smaller cranidia. 



Occurrence. — Boulder B-6, Bic. 



Ty/'^.?.— Holotype : U.S.N.M. No. 123863. Paratypes: U.S.N.M. 

 No. 123864. 



EOPTYCHOPARIA ANGUSTIFRONS Rasetti, new species 

 Plate 3, figures 1-4 



Available material. — A dozen cranidia. 



Description. — The species is so similar to E. normalis that only 

 the distinguishing features are described. The glabella is proportion- 

 ately narrower and in most specimens shows slightly concave sides on 

 account of the anterior part tapering less rapidly than the posterior 

 part. The marginal furrow is more regularly curved, as there is almost 

 no trace of a median inbend, and the border is of more even width. 

 The surface granulation is somewhat more apparent than in E. nor- 

 malis. Cranidia range in length from 2 to 6 mm. 



Remarks. — In the shape of the glabella this species is almost iden- 

 tical with E. taylori (Resser), which, however, has proportionately 

 wider palpebral area and posterior limbs. 



Occurrence. — Boulder B-4, Bic. 



Ty/'^.y.— Holotype : U.S.N.M. No. 123865. Paratypes: U.S.N.M. 

 No. 123866. 



