42 



extremity of the body-chamber. Although the type specimen is not 

 perfect, this curious and interesting little shell appears to be easily 

 distinguishable from all other species of the genus by its compressed 

 conical form, and by the peculiar arrangement of the septa. The writer 

 desires to couple with it the name of its discoverer, Mr. Joseph Towns- 

 end, of Dui'ham, a zealous collector of the fossils of that locality, to 

 whom the Museum of the Survey is indebted for many choice specimens, 

 some of which are described and figured in the present paper. 



TEILOBITA. 



Ceraurus Niagarensis, Hall. 



Oeraunis Niagarensis, Hall. 186Y. Twentieth Eegentw' Eep.. p. 376, 



pi. 21, fig. 10. 



Hespeler, T. C. Weston, 1867: two specimens of the glabella. 



EUEYPTERIDA. 



EURYPTERUS BOTLEI. (N. Sp.) 



Plate 7, Fig. 3. 



Carapace moderately convex, broader than long, greatest breadth a 

 little above the middle ; semiovate, broadly rounded in front and 

 squaj-ely truncated behind ; sides somewhat convex at their margin 

 above, but straighter below ; front and sides bordered by an elevated, 

 narrow ridge, which is highest and most strongly marked on the pos- 

 terior half of the sides. Eyes reniform, prominent, about four milli- 

 metres in the greatest diameter ; nine mm. apart (as measui-ed from 

 the centre of theii- inner margins) and placed at a distance of six mm. 

 from the anterior, and of seven mm. from the lateral margin. Ocelli 

 not clearly indicated, but probably placed on or near a small rounded 

 prominence or elevation, which is situated exactly in the middle of the 

 space between the two eyes. Surface of the carapace apparently finely 

 gi-anulose, and ornamented with minute rounded tubercles, some of 

 which are isolated and others confluent in sets of two or three. 



Thoracic and caudal portions together consisting of twelve segments, 

 exclusive of the telson or caudal spine ; the first, second, third and 



