210 tfEW SPECIES OF FOSSILS.- 



downs ok the exterior of the test, but always well defined m the cast'; 

 lateral lobes bent rather abruptly downwards, having ten ribs, which 

 become indistinct and disappear toward the margin, and are entirely 

 wanting over the narrow space behind the axis ; the anterior ribs shew- 

 jhig a faint median groove toward their vanishing extremities, and a few 

 of the posterior ones bearing feeble tubereulations toward their aiiat 

 extremities". 



The only difference of any importance between the two species 

 appears to be the greater number of rings in the axis of our 

 apecies. This however will most probably turn out to be corre- 

 lated with differences in the glabella. 



Dedicated to Prof. H. How, King r s College, Windsor, Nova? 

 Scotia. 



Locality and Formation, — Kennetcook, Nova Scotia ; lower 

 © arfooniferous. 



Art. XV1IL— Description of a new Trilohite from ike Quebec- 

 Group. By T. Devxne, F. R. G„ S. r G* L. 



Menocephalus Salter!, (ST. s.p.) 

 (Enlarged two diameters.} 



Inscription,.— -form oblong-*— oval. — Entire length three line& ; 

 and width at posterior margin of the head one and one fifth 

 line — front of head and posterior margin of the tail broadly 

 rounded— sides parallel* 



Head — Semicircular, two fifths of the entire length, strongly 

 convex, posterior margin marked by a well defined furrow 

 which curves round the lateral angles anteriorly, 



C5-LABELLA — Ovate, narrow at the base, and broadly rounded in 

 front, extending anteriorly beyond the fixed cheeks, promin- 

 ently convex with a very narrow fiat rim forming an arch 

 round the front. 



Ihqracic Segments — Six or seven, fiat lying close to each other 

 with a broad, deep groove extending outwards to the tips 

 which are bent down. 



