Barton. — Cheiruridae. 



PLATE. 



Fig. 1. Ceraurinus marginatus Barton. A nearly complete, partially en- 

 rolled specimen, the type of the genus and species. The specimen, 

 No. 12 Coll. M. C. Z., is from an unknown formation and locality 

 in Ontario, Canada, but is supposed to have come from the Rich- 

 mond on Manitoulin Island. Natural size. 



Fig. 2. A cranidium of Cheirurus, No. 14 Coll. M. C. Z., introduced to show 

 the character of the basal glabellar lobes in that genus. The 

 specimen is from the Silurian at Wauwatosa, Wisconsin. Slightly 

 less than natural size. 



Fig. 3. Ceraurinus confluens Barton. The imperfect cranidium which is 

 the holotype. The specimen was collected from the upper part 

 of the Trenton at Pefferlaw, Ontario, and is in the Victoria Me- 

 morial Museum at Ottawa, Canada. The figure is one third larger 

 than the specimen. 



Fig. 4. Ceraurinus scofieldi (Clarke) . An enrolled and partly dismembered 

 specimen from the Leray-Black River at Newport, New York. 

 The specimen is No. 13 Coll. M. C. Z., and the figure is twice 

 natural size. The pygidium projects in front of the glabella, and 

 presents its lower surface. 



Fig. 5, 6. Ceraurinus trentonensis Barton. An imperfect cranidium and 

 hypostoma from the lower part of the Trenton on Goat Island, 

 Manitoulin Islands, Lake Huron. The specimens are on a single 

 chip of limestone in the Victoria Memorial Museum at Ottawa, 

 Ontario, and the figures are one third larger than natural size. 



Fig. 7. Ceraurinus icarus (Billings). This figure is made from a copy of a 

 photograph of the specimen figured by Meek, Paleontology of 

 Ohio, 1, plate 14, fig. 11a. The original photograph was made by 

 Mote and Swaine of Richmond, Indiana. The specimen is the 

 type of Ceraurus meekanus Miller. 



