90 NEW YORK STATE MUSEUM 



Remarks. We have three cranidia of this strange type which, 

 representing different growth-stages, have all been figured. No 

 trilobite has as yet been described from the Upper Cambrian which 

 would invite close comparison with this species. It differs from 

 its congeners strikingly in the broad, anteriorly well-rounded, con- 

 vex cranidium and the obscure glabella. Doctor Walcott, to whom 

 the specimens were sent, informs us that he has a very closely 

 related, if not identical form in the upper beds of the St Croix 

 sandstone of Wisconsin. 



The fossil-bearing layer was discovered and the specimens were 

 collected by Prof. H. P. Cushing, to whom the form is dedicated. 



Amphilichas conifrons nov. 

 Plate 30, figures 5-8 



Description. Glabella convex, broadly trapezoidal in outline, 

 about twice as broad as long, projecting medially. Length 23 mm, 

 width about 45+ mm. Median lobe trapezoidal in outline, its pos- 

 terior margin about twice as long as the frontal, very prominent, 

 culminating a little forward of the middle, the apex about 20 mm 

 above the base of the glabella, bent sharply downward in front. 

 The lateral slopes are straight or a little incurved; the posterior 

 slope is gently convex with a suggestion of a ridge. The area of 

 the posterior angles is slightly convex. The first pair of glabellar 

 furrows is sigmoidal, narrow, but fairly deep, ..the posterior portion 

 more strongly curved and extending into the neck furrow. The 

 first lateral lobe is subquadrangular, wider in front, sloping fairly 

 evenly laterally and with the greater portion bent forward ; the 

 second lobe is, as far as preserved, but a narrow strip, apparently 

 broadening at the anterior extremity. The second glabellar furrow 

 is also bent slightly sigmoidal and shallower than the first. The 

 neck furrow is narrow, nearly straight in the middle and curving 

 abruptly forward at the ends. The surface of the glabella is fur- 

 nished with small tubercles and bases of spines which are largest 

 at the apex of the middle lobe. In working out the latter many of 

 the spines were seen to be bent in part and diverging in various 

 directions, as illustrated in the profile view, plate 30, figure 7. 



The pygidium of Amphilichas here described was collected at the 

 same locality and, judging from the rock, possibly in the same bed. 

 It differs from that of the only Trenton congener, A. trenton- 

 e n s i s Hall, and may therefore properly be referred to A . con- 

 ifrons. It is broadly semielliptic in outline, a little contracted 

 in front, about 25 mm long, 30 mm wide in front and 36 mm in its 



