CONTRIBUTIONS TO PALEONTOLOGY. 223 



NOTES AND CORRECTIONS. 



GENUS RETZTA. 



Since the pages relating to this genus were printed, Prof. Agassiz 

 has kindly placed in my hands a series of European species which 

 have been referred to the same designation. An inspection of these 

 specimens shows still more clearly the heterogeneous characters 

 of the material arranged under the generic term Retzia. It is 

 impossible for me, at this time, to give the necessary attention for 

 a proper elucidation of the question involved ; but, should it not 

 be undertaken by some one else, I will endeavor to continue the 

 subject in the next Report on the State Cabinet. 



LICHAS GRANDIS. 



SUB-GENUS? TERATASPIS. 



Thirteenth Report on the State Cabinet. 



In the Fifteenth Report (first published in 1 861 ), I have noticed 

 a remarkable trilobite, under the name of Lichas grandis. The 

 fragment then in my possession preserved only the posterior por- 

 tion of the head. The lateral, or, as they appear to be, the poste- 

 rior lobes of the glabella, are remarkable for their form and 

 prominence, and are studded with strongly elevated nodiform or 

 obtuse spines and shorter node-like tubercles. 



A specimen kindly loaned to me by Rev. Mr. Harris preserves the 

 anterior lobe, and very imperfectly the posterior lobes, which, as 

 in the other specimens, are partially divided by a shallow groove. 

 More recently, Prof. Ward of Rochester has placed in my hands 

 a collection of specimens exhibiting a part of the head, preserving 

 the anterior and posterior lobes of the glabella, together with a 

 pygidium, and one or two other specimens. At the same time, I 

 have obtained from Col. Jewett a portion of a pygidium which 

 apparently belongs to this species. 



These fragments, taken together, present points of difference 

 from the ordinary forms of Lichas, which may render a separation 

 from that genus necessary. The anterior lobe is round and ex- 



