388 The American Geologist. June, i892 



the extremity, of the pygidium, and is rounded at the anterior 

 corners. 



Locality. St. John group, at Porter's brook. 



This species is of the type A, %)ctrvifrons Linrs. 



Section III, LIMBATI. (xeneral form subquadrate, head 

 has a broad limb, basal lobes large. The cheeks in front of the 

 glabella are not divided by a central groove or grooved at the 

 sides. The p3'gidium is usually produced into lateral spines. 

 {Agnostus rex Barr, pi. x fig. 13). 



Series A. (REGII). Distinguished by its broad limb, dimin- 

 ishing cheeks and side lobes of the pygidium. Both the anterior 

 lobe of the glabella and the posterior lobe of the pygidium ex- 

 pand. (Type Agnostus rex Barr). 



Series B. (FALLACES). This series has a smaller head, and 

 moderately broad limb. Cheeks large; basal lobes rather large 

 with a broad posterior lobe to the axis of the pygidium. (Type 

 Agnostus f alia X Linrs, pi. x, fig. 2). 



Agnostus vir Matthew, 1885. Pi. x, flg. 14. 



Diagnosis. — Head elongate, semi-elliptical, with straight sides 

 and angulated behind. Dorsal furrow distinct. Marginal fold 

 and groove rather flat and broad. G-labella subconical, obtuse in 

 front, expanded ])ehind. Length about five-sevenths of that of 

 the head. The anterior lobe of the glabella is about two-fifths 

 of its length; it is elliptically rounded in front, and obtusely 

 behind; the posterior lobe is narrowed behind, and in that part is 

 decidedly elevated above the rest of the head; a sigmoid furrow 

 cuts ofl[' a depressed basal lobe on each side. The cheeks are 

 moderateh' elevated, and of equal width all around the glabella. 



The thorax consists of two segments, the first is divided into 

 three lobes of which the outer pair is globose, the axis is elon- 

 gated, transverse and indented on the front side by two strong 

 furrows extending ^ wa}^ across ; the second segment is similar to 

 the first, except that there are no grooves on the axis. 



The pygidium is subquadrate, and armed with two lateral 

 spines: its width one-fifth greater than its length. Axis cylin- 

 dro-conical, obtusely pointed behind, and bears an elongated 

 tu])ercle pointed backwards. The side lobes of the pygidium are 

 about ^ the width of the axis and narrowed towards the posterior 

 end of the pygidium, where they connect. The marginal furrow 



