No. 2. — The Chimaeroids (Chmyiopnca Raf., 1815 ; Holocephala- 

 Miill., 1834), especially Bhiiiocldmaera and its Allies. By 

 Samuel G arm ax. 



There are few of the marine animals that on account of structure and 

 relationships to other forms living ami extinct hive as great interest for 

 zoologists and palaeontologists as the Chimaeroids. Their line of descent 

 extends to Devonian times and away beyond and back to a meeting with 

 that of the Plagiostoraia near the point at whicli the latter separated from 

 the bony fishes. That the line has been well traced fur a long distance 

 through the fossils only makes it the more interesting. Item after item 

 of information relating to the group has been carefidly gathered, dis- 

 cussed, and placed on record, but the advances among the recent have 

 been very slow, and those among the fossils, though in some ways much 

 more extensive, have left much to be desired. The type species of Chi- 

 niaera and Callorhynchus have been known since the establishment of 

 these genera by Linne and Gronow, in 1754. jNIore recently other species 

 have been added to each of them. A most important addition to the 

 knowledge of the group dates from the capture of the types of the genus 

 Harriotta, by the United States Fish Commission, and their description 

 by Messrs. Goode and Bean, in 1894, and a little later another was made 

 by the discovery of a Japanese species, by Professor Mitsukuri, in 1895, 

 which was placed in the same genus, named but not described. The 

 importance of the species from Japan was not recognized for some years, 

 until Dr. Alexander Agassiz, returning from one of his explorations of 

 the Coral Islands, saw and purchased a second specimen from a dealer in 

 Tokyo. Dissection of this specimen supplies the reason for existence of 

 this paper; it brings to liglit a number of interesting details concerning 

 Chimaeroids, and some wliich pertain to other forms than that directly 

 under consideration. The following are among the results and conclu- 

 sions, brought prominently forward at this moment, that appear to be 

 most worthy of attention. 



The species, Rhinochimaera pacifica, is described and figured with 

 details of skeletal and other anatomy. 



VOL. XLI. — NO. 2 



