392 E. Billings on Prof, HalVs recent publication, 



who may have occasion to read Prof. Hall's papers to examine 

 them closely, as it is not unusual for him — especially in questions 

 of priority — to arrive at decidedly erroneous conclusions. 



I shall now proceed to point out a few palseontological errors 

 in his new work. 



1. The genus Cryptonella, illustrated on PI. 3, p. 133, is pre- 

 cisely identical with CharioneUa^ described by me in the Cana- 

 dian Journal of March, 1861, p. 148 and illustrated in the May num- 

 ber, p. 2*73, 274. It includes the species described by Prof. Hall 

 in the Thirteenth Report under the names of Meristella Haskinsi^ 

 M. Barrisi, M. Doris, Terehratula Linckheni. T. rectirostra 

 T, lens, and T.planostria. Besides these the Atrypa scitula oi 

 the N. Y. Reports, C. Circe, and apparently a number of Euro- 

 pean species belong to it. Crijptonella was first published in July 

 or August, 1861, three or four months after the learned author 

 became acquainted with its characters through the study of my 

 papers. 



2. Centronetla impressa, PI. 3, figs. 1-5, is C, Hecate published 

 by me in the Canadian Journal, May 1861, p. 272. The date of 

 Prof. Hall's description is July or August of the same year. 



3. Euomphalus {StraparoUus) (jlymenioides, PI. 6, fig. 3, is 

 Straparollus Canadensis described by me in the begining of July 

 1 86 1, in the Canadian Journal Prof. Hall's species was published 

 in October 1861. 



4. At page 166 we have the plate with the suppressed 

 figure of Conrad's genus Cypricardites, well copied in full- 

 Palaeontology is indebted to me for the publication of this 

 important plate. Had I not described the genus Cyrtodonta, 

 I fear it would have remained for ever in the dark. The 

 reason given by Prof. Hall for publishing it now is simply 

 that I charged him, in a respectable journal, with holding it in 

 his hands for eighteen years without publication. I here reiterate 

 that charge. There was no mention made of this figure in any 

 of Prof. Hall's publications from the time it was drawn in 1840^ 

 or thereabouts, until the yea 1859. His ideas with regard to 

 the laws of scientific nomenclature are not correct. The rule ap- 

 plicable in this case is, that if a name imply that the genus 

 belongs to a family, order, or class different from that to which it 

 does actually belong, then it should be changed. For example, if 

 the Trilobite Bathynotus were to be called Bathyocrinus or Bathy- 



