160 SYNOPSIS OF THE CHARACTERS OF THE 



Calymene Latreillii. Stein. 



Calymene Latreillii. Stein. Mem. Geol. Soc. Fran. — Calymene Latreillii. Phil. Pal. Fos. 

 One or two frao-ments of the post-abdomen of a species resembling tliat figured by Professor Phillips, have 

 occurred, but too imperfect for correct identification or description. 



Griffithides. Portk. 

 The genera PhiUipsia and Griffithides, so common in the carb. limestone, are very distinct in their charac- 

 ters. In Phi/lipsia the glabella is as wide at the base as in front, and marked on each side with three cephalo- 

 thoracic furrows, which in Griffithides is gibbous in front, but contracted to a very narrow neck at the base, and 

 there are no lateral furrows ; the eyes in the former are usually larger and reticulated, while in the latter they 

 seem smooth. 



Griffithides calcaratus. M'Coy. (PL IV. fig. 3). 



Sp. Ch. Cephalo-thorax, semioval; glabella smooth, ovate, most convex in the middle of its length; 



cheeks small, triangular, flat, smooth ; wings strongly striated, broad, prominent, rounded, terminating poste- 

 riorly in long, flattened spines ; eyes moderate, lunate (smooth ?), connected with the glabella by a nucleus on 

 each side ; pygidium with a smooth margin, each segment with a row of very minute granules. 



This beautiful species is most nearly alHed to the G. longispimis, Portk., but is at once distinguished by 

 its smooth cheeks ; the eyes also, in the present species, are differently formed and placed, and the glabella is 

 much smaller and less prominent in front. Length of glabella five lines, greatest width three lines ; width at 

 base one line, width of cephalo-thorax seven lines ; length of eyes one and a half lines, width one line ; length 

 of posterior alar spine three lines. The Pygidium has a broad, smooth, margin or limb, in which it difiers 

 from that of the G. lonr/ispinus, in which the segments are extended to the margin; there is a single row of 

 very minute granules on each segment. Width of pygidium five lines. 



Griffithides globiceps. Phil. sp. 



Asaphus globiceps. P/iil. Geol. York. — Griffithides globiceps. Portk. Geol. Eep. 



Sp. Ch. — Cephalo-thorax semioval; glabella pear-shaped, very gibbous, globose in front; cheeks triangu- 

 lar, convex ; eyes small, lunate, smooth, connected by a nucleus with the base of the glabella ; wings broad, 

 convex, with strong, imbricating, longitudinal striae'; extremities acutely angular; axal and lateral lobes of the 

 abdomen and pygidium nearly equal, very tumid ; pygidium obtusely rounded ; entire surface smooth. 



Specimens, with the cephalo-thorax, abdomen and pygidium in contact, are not uncommon. 



Griffithides granuliferus. Phil. sp. 



Asaphus granuliferus. Phil. Geol. York. 



Sp. Ch. — Pygidium obtusely rounded; length four-fifths the width; axal and lateral lobes nearly equal, 

 tumid ; surface covered with rather distant, very minute granulations. 



I have never seen this species much more than half the size of the specimen figured in the Geology of 

 Yorkshire : the minute, scattered granulations easily distinguish it. 



Griffithides longiceps. Portk. 



Griffithides longiceps. Portk. Geol. Eep. 

 Pygidium semi-oval, obtusely pointed ; axal lobe large, with about ten or twelve rows of small tubercles ; 

 lateral lobe depressed, with about eight rows of tubercles. 

 I have only seen the tail of this species. 



