28 



about 16 smooth rings — the anchylosing of the posterior 

 rings renders it difficult to determine the exact number. 

 The lateral lobes are marked by 6 broad, pleurse — the 

 posterior pair unite back of the posterior termination of 

 the axial lobe. 



Formation and Locality. Trenton Limestone, Min- 

 eral Point,' Beloit and north of Janesville, Wisconsin." 



Compare Crypt, sexcostatus and Crypt, deltoideus. 



Cryptonymus Tkentonensis. Walcott, 1877. 



Desceiption of New Species of Fossils, from the Chazy and 

 Trenton Limestone, P. 16. 



"Pygidium triangular, convex ; length and breadth 

 about equal ; axial lobe rounding, tapering toward and 

 terminating within the posterior margin ; marked by 23 

 rings, beyond which there are several, too indistinct to 

 be counted ; the first anterior ring has a node at its cen- 

 tre ; then, in order, the 3, 6, 10, 14, 18 and 22 have a 

 similar node at the centre. Lateral lobes slope rapidly 

 to the margin ; each has 9 elevated costse running ob- 

 liquely backward to the margin. 



Formation and Locality. Clifton, Grant county. Wis., 

 and two miles above Duulith, 111., north of State Line 

 monument." 



This species has certain affinities with Cryptonymus 

 Nereus, Hall, and it may be identical ; although the axis 

 represented in the copy of the cast figured in the 20th 

 Regents' Report, N. Y. State Cabinet, does not show the 

 tubercles along its centre. 



