Bibliography. 51 



38 John M. Clarkk. JVew ov Rare Species of FoHsiUfi-om the Jwrimns of 

 the Livonia Salt Shaft. (Thirteenth Ann. Kept. N. Y. State Geohtgist, 

 vol. 1, p. 177, pi. IV, figs. 19-22. Also in Forty-seventh Annual 

 Report N. Y. State Museum, p. 371.) 



Descriljes as Hyahsteliu? Marcellia, a species from the hituminous 

 shales of the Marcellus epoch, the generic characters of which are (piite 

 obscure, though the presence of broad unresolvable spicules of great size and 

 having the form of blades of grass, indicates a structure unlike any heretofore 

 described. The original fonn of the species is unknown. 



1895. 



39. K. A. v. Zi'iTEL. Grundzilge der Palaeontf}lo(/ie, jyp. 52 et seq. 



The author here recognizing the two suborders of the Hexactinellida, 

 Lyssacina and Dictyonina, places under the former the three families, Pro- 

 TospoNGiD^, DicTYospoNGiD^ and Plectospong iD^. The definition of each of 

 these families is essentially that given by Rauff. 



1896. 



40. K. A. VON ZiTTEL. Text-hooTc of Palaeontology ; Translated and edited hy 



Charles P. Eastman, pp. 54 et seq. 



The subject is here treated as in No. 39, of which this is a translation 

 and enlargement. 



41. George II. Girty. A Pevision of the Sponges and Coelenterates of 



the Laiver Helderberg Fauna of New Yorh. (Fourteenth Ann. Kept. 

 N. Y. State Geologist, pp. 258 et seq. Also Forty-eighth Annual 

 Report N. Y. State Museum, p. 261.) 



For certain hexactinellid spicules from the Lower Helderberg rocks the 



author introduces the generic term Lysactinella and makes use of two 



specific names, one applied to smooth spicules, the other to those having 



thorny rays. 



1897. 



42. Ferdinand Roemer and Fritz Frech. Lethcea Geognostica, 1 TJieil ; 



Lethcea Palceozoica, 1 Band 



This is a continuation of Roemer's work, the plates of which appeared in 

 1876 and the first instalment of the text in 1880. So far as the Dictyosponges 

 are concerned no additions or changes are made from the treatment of the 

 genera as cited under No. 8. 



