PALEONTOLOGY. 295 



for tlio considerable variation of the Grasteropod in its '^general form, 

 configuration ol'tlie aperture, and tlie surface markings." In spite of 

 the clear recognition of this plasticity of form the author has been una- 

 ble to resist the temptation to name and define in terms of these plastic 

 characters the four new species above mentioned. 



THE CEPHALOPODA. 



Alpheus Hyatt (121) has presented a valuable paper, strictly biological, 

 in which he discusses the value of embryological characters in the deiini- 

 tion and classification of the Cephalopoda. He proposes a new nomen- 

 clature for the stages of development of the embryo, and applies the 

 classification in distinguishing the various stages represented by the 

 fossil Cephalopoda. In a brief review it is impossible to give the sub- 

 stance of this paper, and those interested are referred to the article 

 itself, which is fully as interesting as the important works on similar 

 subjects which Professor Hyatt has already published. Professor Hyatt 

 also read a paper before the ISTational Academy, at the Boston meeting, 

 on the primitive forms of Cephalopods (119), an abstract of which is 

 given iu the American Naturalist, as above cited. It is difficult to ex- 

 press in briefer words the contents of this valuable paper. The author 

 discusses the phylogeuetic relations of the Paheozoic and later Cepha- 

 lopods, particularly in respect to their characters of curving, from the 

 straight coiled form, as seen in Orthoceras, to the close coiled Nautiliau 

 form. 



In the report of Contributions to Canadian Pala3ontology, by Pro- 

 fessor Whiteaves (292), two generic descriptions are communicated by 

 Professor Hyatt (120) from theTriassic rocks of British Columbia. The 

 names are — 



Arniotites, Hyatt, geu. iiov., p. 144, type Balatonites arictiformis, Mojsisovics. 

 Dorikraniies, Hyatt, gea. nov., p. 145, type Balatonites Bagdoamis, Mojsisovics. 



Arthur H. Foord (86) publishes a note on the genus Actinoceras with 

 Ijarticular reference to specimens in the British Museum showing the 

 perforated apex of the Siphuncle; the specimens illustrated are from 

 the Trenton and Black River rocks of the United States, British North 

 America, and Arctic America. The same author (87) writes on the 

 genus Piloceras Salter, as elucidated by examples lately discovered in 

 North America and Scotland. The bibliography of the genus is re- 

 ferred to, the internal structure is described and illustrated, and the 

 characters discussed, based upon study of Scotch and American speci- 

 mens. 



ARTHROPODA. 



A. S. Packard published in 1887 several memoirs which were read 

 before the National A(;ademy of Sciences in 1SS5, and their contents 

 have already been rei)orted in the scientific .journals. 



The first (218a) "On the Syncarida, a hitherto undescribed synthetic 

 groupof extinct Malacostracous Cntatacea''^ (vol. iir, p[). 12;>-128, and two 



