TRILOBITA—OPISTHOPARIA. 289 



XXXVII. AsAPHiscus Meek. 



Very similar to Bathyuriscus but differs in the characters of the 

 cephalon. Anterior to the depressed, conical glabella is a broad 

 fold separated from the raised marginal rim by a broad furrow; 

 eyes more anterior and farther from the glabella. No genal spines 

 present. Cambric. 



87. A. wheeleri Meek. (Fig. 1596.) Cambric. 



Fig. 1594. Bathyurus 

 exta ns. ( After Logan. ) 



Fig. 1595. Bathyurus 

 S77iithi. (After Logan.) 



Fig. 1596. Asaphiscus 

 wheeleri^ partly restored 

 type specimen, X %• 

 (After Walcott.) 



Cephalon depressed. Segmentation of pygidium indistinct. 

 Middle Cambric of Utah and Nevada. 



XXXVIII. Ogygopsis Walcott. 

 Cephalon and pygidium well developed. Eye lobes not very 

 strongly arched nor very close to the glabella. Thorax wider near 

 pygidium than at cephalon. Geniculationof pleura recedes farther 

 and farther from the axis in going backward. Pleura grooved. 

 Cambric. 



88. 0. klotzi Rominger. (Fig. 1597.) Cambric. 



Cephalon, thorax and pygidium nearly equal, with pygidium 

 slightly the longest. Glabella with parallel sides; the three gla- 

 bellar furrows very faint. Thoracic segments eight, remarkably 

 parallel and at right angles to axis until at the margin they bend 

 slightly backward into short spines. Segments of pygidium (11 



