8 



of Trilobites, pointed out the discrepancy between the 

 two figures referred by Bronginart (plate i, fig. 3a-b,) 

 to Calymene variolaris, and cited the erroneous 13 seg- 

 mented C. variolaris, Murch., under the genus Calymene, 

 and Brongniart's 11 segmented figure under the genus 

 Phacops. He also correctly refers the Calymene vario- 

 laris of Brongniart's pi. i, fig. 3a, under C. punctatus. 



In 1843, Prof Hall, in a pamphlet on the Trilobites 

 of the Inferior Strata of New York, describes Oeraurus 

 ( Oryptonymus) vigilans. 



Emmrich, in Zur Naturgesch. der Trilobiten, 1844, 

 in reclassifying the genus Oalymene, clearly indicated, 

 though not well described, the divisions of this family 

 in creating the genus Encrinurus, with the following 

 generic formula : ''Encrinurus nov. gen. (der schwanz 

 und Encrinites) — Eyes smooth, the glabella inflated, 

 and club-shaped, the pygidium with a many ringed axis 

 and few pleurae. Entomostraciles punctatus, Wahl., is 

 so different from all other trilobites, that it is entitled to 

 form a separate genus ; it unites the clavate glabella 

 of the Asaphus, and has the facial line and eyes like 

 Calymene. The facial line is an intermediate between 

 the genera Calymene and Phacops. On account of its 

 peculiar shaped pygidium, I have given it the above 

 name. In addition to the above named, two of Port- 

 lock's species belong to this genus, viz : Amphion mul- 

 tisegmentatus and Ogygia rugosa." 



In 1845, Loven, in the Trans. Swedish Royal Acad, 

 of Science, p. 110, proposed the genus Gybele for such 

 types as Calymene hellatula, Dalm., and referred to this 

 genus Caly. verrucosa and Caly. velata. Judging from 



