Genus Agnostus. — Yogdes. 385 



The species differs in minor points from A. gihhus var. hyhridus Brog- 

 ger, especially in having an elongated ridge on the front of the posterior 

 lobe of the glabella. 



Agnostus obtusilobus Matthew, 1885. Plate ix, fig. 3. 



Cf. A. scarceoides Salter, 1872, from which it differs by a nar- 

 rower glabella with a more obtuse frout. 



Diagnosis. — The head of this species is like that of A. acuti- 

 loha Matthew. The pygidium described under this name is sub- 

 quadrate in form, wider behind than before, and has a pair of 

 spines at the outer angles. The axis is nearly one-half as wide 

 as the pygidium, about four-fifths of its length and projects for- 

 ward beyond the side lobes ; it is obtusely lanceolate, somewhat 

 narrowed in the middle, and divided into three lobes, of which 

 the posterior is a ^ longer than the length of the two anterior. 

 The middle lobe is elevated in the middle, and bears an elongated 

 tubercle on the axial line; there is also a faint tubercular eleva- 

 tion on the middle of the anterior lobe. The lateral lobes of the 

 pygidium are somewhat narrowed in the middle of their length by - 

 the projecting sides of the axial lobe, and rapidly behind the 

 pygidium, where they connect. The dorsal furrow is deepl}" im- 

 pressed all around, and at the posterior angle is ver}' close to the 

 marginal furrow; this furrow is angled forward to the axial lobe 

 and quadrately rounded at the posterior side of the pygidium. 

 Locality. St. John group, Porter's and Hanford brooks, St. Martin's. 



Agnostus tessella Matthew, 1885. Plate ix, fig. 4. 

 Diagnosis. — Head semi-elliptical, higher in the middle and 

 rear part. Dorsal furrow distinct on the posterior f of the gla- 

 bella, faint on the other ^. Limb strongly elevated ; the interior 

 groove deep and strongly impressed. Griabella cylindro-conical, 

 rounded in front, the width ^ of that of the head; the length five- 

 sevenths. The frontal lobe of the glabella is depressed to the 

 level of the cheeks, and almost obsolete; the posterior lobe is 

 cylindrical, rounded behind, bounded in front by a straight, deep 

 furrow, and bears a small tubercle ^ from the front. Basal lobes 

 small. ' Thorax of two segments. The anterior segment bears 

 five lobes of which the two lateral pairs are globose; the axis is 

 transversely elongated, wider behind than before, and bears a 

 minute tubercle at the axial line. The posterior segment is simi- 



