162 SYNOPSIS OF THE CHARACTERS OF THE 



be little doubt, If better known, it would form a genus distinct from any of those ali-eady constituted ; I have 

 named it from tlie great difference in number of the segments of the axal and lateral lobes of the pygi- 

 dium. Length of pygidiura three lines, width four and a half hues, width of axal lobe one line. 



Phillipsia GEMMULIFEEA. Phil. SP. 

 Asaphus gemmuliferus. Phil. Geol. York. 

 Sp. Ch. — Pygidium obtusely rounded, narrow; with three nearly equal, convex lobes, each lobe with six 

 longitudinal rows of small tubercles. 



This species strongly resembles the P. truncatula, but is constantly smaller and more convex. Length 

 of pygidium five lines, width five lines. 



Phillipsia Jonesii. Portk. 



Phillipsia Jonesii. Portk. Geol. Rep. 



Sp. Ch. — Longitudinally oval, twice as long as wide; glabella one-third the entire length, very broad, 

 depressed, obtusely rounded in front, contracted in the middle ; eyes very large, reniform, more than half the 

 length of the glabella ; cheeks small, narrow, slightly convex ; sui-face covered with minute, rather distant, im- 

 pressed puncta ; abdomen and pygidium smooth. 



This species is easily recognized by its very broad, depressed glabella, which is somewhat hour-glass 

 shaped, being remarkably contracted in the middle ; many specimens are found rolled up. Length of cephalo- 

 thorax four lines, width five lines. 



Phillipsia Kellii. Portk. 



Phillipsia Kellii. Portk. Geol. Rep. 

 This pretty little species is intermediate between the P. truncatula and P. Jonesii ; it is about the size 

 of the latter species, but resembles the former in tlie tuberculation of the jDygidium, which is also more obtuse 

 at the extremity than in that species; there are six rows of granules on each lobe of the pygidium. The head 

 resembles that of the P. Jonesii, but is longer in proportion to the width, has smaller eyes, and the glabella 

 has more nearly parallel sides. 



Phillipsia Macovii. Portk. 



Phillipsia Macoyii. Portk. Geol. Rep. 

 The only specimen which has occurred of this species I collected myself from the carboniferous limestone 

 of Kddare ; it was lent to Captain Portlock for liis Monograph of Lish Trilobites, as I conceived it to be not 

 only a new species, but the type of a new genus. I am still inclined to think it cannot be ranked with any 

 known genus ; the very small size of the glabella, and large size of the eyes, distinguish it from the most 

 nearly aUied, and from Phillipsia, with which Captain Portlock has ranked it, it is distinguished by the want 

 of the cephalo-thoracic furrows. As I have, however, no means of examining the specimen now, I cannot 

 characterize it. Length of cephalothorax two lines, width three lines. 



Phillipsia mucronata. M'Cot/. (PI. IV. fig. 5). 



Sp. Ch. — Pygidium semi-elliptical, terminating posteriorly in a short, mucronate, obtuse point; axal lobe 

 nearly as wide as the lateral ones ; about fifteen axal and nine lateral segments ; surface smooth. 



This is the only Trilobite I know of in the Mountain Limestone with a mucronate or pointed tail. 

 Length of pygidium four lines, width five lines. 



Phillipsia quadriserialis. M'Coy. (PI. IV. fig. 8). 

 Sp. Ch. — Pygidium semi-oval, slightly wider than long; of fifteen axal and twelve lateral segments; each 

 lobe bearing four rows of large tubercles ; Umb narrow, flattened, smooth. 



