Febeuaey 5, 1904.] 



SCIENCE. 



217 



.The total niimber of species of Salmon- 

 id£E now known from Alaskan waters is 17, 

 distributed among genera as follows : Core- 

 gonus, 3 ; Argyrosomus, 3 ; Stenodus, 1 ; 

 Oncorhynchus, 5 ; Salmo, 3 ; Cristivomer, 

 1, and Salvelinus 1. Of the closely related 

 family of Thymallidje there is one species, 

 Thymallus sigiiifer. This number is much 

 greater than is known from any other re- 

 gion; and as regards the number of indi- 

 viduals of important species of Salmonidai, 

 there is no other region that approaches 

 Alaska. The Pacific salmons (of the gemis 

 Oncorhynchus) are by far the most abund- 

 ant, one or more of the five species liter- 

 ally swarming in every suitable stream at 

 spawning time. These are all anadromous 

 fishes, spending the greater part of their 

 lives in salt water, entering fresh-water 

 streams only for spawning purposes. Im- 

 mediately after spawning all the individ- 

 uals of Pacific salmon, of whatever species, 

 die, none surviving the spawning act and 

 none ever returning to the sea. The eggs 

 do not hatch until several weeks or even 

 months after the fish that produced them 

 have died, and, therefore, no Pacific salmon 

 ever saw either its offspring or its parents ; 

 the generations never overlap. Wliile 

 many of the facts in the life histories of 

 these salmon are now well known, there 

 are many others which remain to be worked 

 out. The Bureau of Fisheries is now 

 taking steps looking towards a careful and 

 thorough study of the salmon streams of 

 Alaska and the life histories of the various 

 species of salmon. During the recent in- 

 vestigations of the Alaska Salmon Commis- 

 sion many important facts were determined 

 regarding these fishes. Much new informa- 

 tion was secured regarding the habits and 

 distribution of the Dolly Varden trout and 

 the cut-throat trout, and the presence of 

 a species of rainbow trout in southeast 

 Alaska was first made known. A fine se- 

 ries of specimens of the fishes of the upper 



Yukon, including the Arctic grayling, was 

 also secured. 



'^Preliminary Description of a New Family 

 of GymnoUastic Hydroids from the Ha- 

 waiian Islands: C. C. Nutting, Univer- 

 sity of Iowa. To be published in con- 

 nection with a report on the hydroids of 

 the HaM^aiian cruise of the Albatross, 

 U. S. Bureau of Fisheries. 

 The Development and Relationships of the 

 Bugosa {Tetracoralla) : J. E. Dubrdetst, 

 University of Michigan. 

 The paper gives: (1) A brief historical 

 account of the various theories which have 

 been held with regard to the nature and 

 relationships of the extinct group of corals, 

 the Rugosa or Tetracoralla; (2) the con- 

 clusions of the author from the examina- 

 tion of a large number of species in the 

 light of more recent results on living Zoan- 

 tharia. At different times the Rugosa have 

 been supposed to be related to the Hydro- 

 zoa, Ceriantheffi, Alcyonaria, Scyphome- 

 dtisEe and modern hexameral corals. The 

 last view prevails mostly among English 

 "writers, the distinctness of the group being 

 maintained by most German and French 

 authors. The present investigations have 

 been carried on mainly by the method of 

 grinding down of individual coralla, each 

 successive stage in the growth being dra"wn 

 as it appeared. In this way the complete 

 development and relationships of the septa 

 have been established. In every instance 

 where the perfect tip has been preserved 

 a cycle of six septa is found to occur, thus 

 demonstrating the primary hexameral re- 

 lationships of the Rugosa as contrasted 

 with the tetrameral usually assumed. The 

 subsequent septa appear in only four of 

 the six primary chambers and in a manner 

 differing altogether from that in modern 

 corals. The conclusions reached are that 

 the Rugosa must remain as a distinct group 

 of the Zoantharia, related in their proto- 



