14 



both, would be equal to 3 plus 5, which is 8. Xow, if 

 we take away the Asaphus, or the number 3, the IIIcfh' 

 us, or 5 remain?. This number cannot alone establish 

 the genus Cryptonymus. ******** * 

 The new genus Cryptonymus, established from the for- 

 mer name, meets with the same objection that the older 

 genus had : for it was established upon two altogether 

 different genera, viz: Zethus and Encrinurus. The 

 former calculation reappears with the same consequence ; 

 the younger genus Illarnus having replaced that of 

 Cryptonymus of 1825, so also will the Encrinurus of 

 1844 be substituted for the Cryptonymus of 1840." 



In 1S65, Billings, in his work on the Palaeozoic Fos- 

 sils of Canada, vol. i, describes Encrinurus mirus, on 

 p. 292, fig. 282. 



In the Catalogue of Silurian Fossils of Antic, Anti- 

 costi, which was published in 1866, the Encrinurus elc" 

 gantulus, Billings, is described. 



In 1867, Prof. Hall described Encrinurus nereiis, id 

 the 20th Eegents' Eeport, X. Y. State Cabinet, p. 375. 



In 1 874, Steinhart described and represented Encrin. 

 punctatus, in the Beit, zur Xatur., Preussens, ou p. 57, 

 Tab. iv, fig. 15. 



In 1875, Hall and Whitfield (Geol. of Ohio, vol. ii, 

 part 2,) describe Ericnnurus ornatus. 



In 1877, Walcott described the following species : 

 Encrinurus raricostatus and E. Trentonensis, in a pam- 

 phlet published in advance of the 29th Regents' Report 

 of the Xew York State Cabinet. 



Miller, in his Catalogue of American Palfeozoic Fos- 

 eils, part Crustacea, gives a list of the Isorth American 

 Trilobites. 



