October, 1913. New Trilobites — Slocom 59 



lobes observed is that attached to the fixed cheek. This is elevated, 

 lunate in form with the convex side toward the dorsal furrows. The 

 marginal border of the cephalon is represented only by a single some- 

 what crushed fragment, but this fragment indicates that there was 

 a narrow marginal border similar to that of A. bicornis Ulrich. Eyes 

 and free cheeks not preserved. Surface of the cephalon finely papil- 

 lose, with tubercles of various sizes more or less regularly arranged 

 thereon. Two of the larger of these tubercles occur along the median 

 line of the glabella, one on each lateral lobe, and three form a transverse 

 row on the occipital segment; aside from these tubercles, the inflated 

 anterior portion of the glabella supports a pair of recurved hornlike 

 processes, 2.5 mm. in diameter and 29 mm. long (measured on the outer 

 side of the curve) ; these processes diverge somewhat and curve upward, " 

 then backward. Another pair of processes of about the same size 

 occurs; one on each lateral lobe of the glabella, near the dorsal furrow, 

 in line with the eyes. Exact length of the lateral pair of processes not 

 known. 



Thorax and pygidium unknown. 



The specimen (Mus. No. P 11181) on which the above description is 

 based consists of a nearly complete cranidium of which the inner sur- 

 face of the test is exposed with one of the anterior horns complete and 

 in natural position and one of the lateral ones bent outward with the 

 end missing. The dimensions are as follows: Length of cranidium, 

 along the median line, 32 mm.; greatest width of glabella (in front of 

 eyes) 42 mm. ; width of median glabella lobe on anterior margin 18 mm. ; 

 width at occipital furrow 11.5 mm.; width of lateral lobes 11.5 mm.; 

 width of occipital segment on median line 7 mm.; width at dorsal 

 furrows 5.5 mm. 



Remarks. — In general form and proportion the cranidium above 

 described approaches A. bicornis Ulrich, from a similar horizon in 

 Minnesota, but is distinguished from that species by the number and 

 position of the hornlike processes as well as by the variation in size of 

 the surface tubercles; also in a side view of the glabella of A. bicornis the 

 outline of the surface is convex, while in A. rhinoceros the outline near 

 the middle is concave, due to the inflation of the anterior portion. 



Locality and horizon. — Upper layers of the Lower Maquoketa beds 

 at Elgin, Iowa. 



Amphilichas clermontensis sp. nov. Plate XV, Fig. 7. 



Type specimen No. P 11 257 Field Museum. 



Cephalon subtriangular, broadly rounded anteriorly, much shorter 

 in proportion to the width than A . rhinoceros. Glabella convex, great- 



