October 7, 1904.] 



SCIENCE. 



463 



results of that study, has provided a check 

 list of the Decapoda inhabiting the coast from 

 southern California northward. An efiort 

 has been made to figure aU the less known 

 species. When it is considered that the basis 

 of this study includes the rich collections of 

 the U. S. Fish Commission from Lower Cali- 

 fornia to the Arctic; the extensive explora- 

 tions on the Alaskan coast and the Aleutian 

 islands made by Dall; and the fruit of lesser 

 researches by a large number of collectors and 

 students, including Stimpson, Lockington and 

 Holmes — in all some 50,000 specimens — it can 

 be realized how extensive and valuable an 

 addition to our knowledge of the Crustacea 

 of the north Pacific is embraced in Miss Eath- 

 bun's painstaking memoir. 



The decapod fauna of the north Pacific is 

 rich in individuals if not in species. Certain 

 types were found in especial profusion, such 

 as the shrimps belonging to the Pandalidse, 

 Hippolytidae and Crangonidse, the hermit 

 crabs, the maioid spider crabs and the Lith- 

 odidffi or anomouran spider crabs. The Pan- 

 dalidse take the lead in numbers. The most 

 abundant species are Pandalus iorealis and 

 a subspecies of the Atlantic P. moniagui, 

 boreal forms which extend southward from 

 the Arctic into both oceans, but seem to find 

 the most favorable environment in the Pacific. 



In number of species the genus Spironio- 

 caris of the Hippolytidae is unsurpassed, being 

 represented in the north Pacific by fifty-one 

 species exhibiting great diversity of form, 

 several of which are also common to the 

 Atlantic. Like Pandalus, it is essentially a 

 boreal group. The Crangonidse also occur in 

 great numbers and include thirty-two different 

 forms, mostly restricted to the Pacific. The 

 hermit crabs are also very abundant and to 

 some extent rather local, occurring in their 

 finest development in a special region, out- 

 side of which these species are often rare and 

 stunted. 



In their distribution many of the Arctic 

 forms continue southward on either shore to 

 the Kurile Islands, on the one hand, or Puget 

 Sound, etc., on the other. As with the mol- 

 lusks, fishes and marine mammals, the winter 

 line of floating ice in Bering Sea determines 



the northern limit of many forms. While 

 many species run without interruption from 

 this limit south to California, the distribu- 

 tion of others indicates the possible division 

 of the fauna geographically into subfaunse, 

 points of limitation being indicated near Ka- 

 diak, Puca Strait and Monterey, California. 

 Some Bering Sea species occur sporadically 

 in the cold waters of glacier-fed bays in south- 

 eastern Alaska, where they are, perhaps, relics 

 of that glacial time when the immediate 

 waters of the whole coast were much colder 

 than at present. A few Japanese species also 

 appear sporadically in analogous latitudes on 

 the American coast, without, so far as known, 

 inhabiting the intervening region. The archi- 

 benthal species, as was to be expected, have 

 a greater range than those restricted to the 

 more variable environment of the shallow 

 waters of the coast. 



The memoir is abundantly illustrated and 

 will be of permanent value to all interested 

 in the natural history of the Crustacea. 



Dr. Richardson's paper includes a list of 

 the isopods collected by the Harriman expedi- 

 tion, together with others obtained on the Cali- 

 fornian coast by Professor W. E. Eitter. In 

 all, twenty-one species are enumerated, of 

 which five are regarded as new, while the 

 doubtful Idotea gracilUma is reidentified, fig- 

 ured and redeseribed. A Munna was taken 

 at the Pribiloff Islands in a state too muti- 

 lated to describe, but the presence of a species 

 of this family heretofore unknown from the 

 Pacific coast is a fact of interest. 



Dr. Holmes describes six new amphipods 

 and enumerates sixteen others from the col- 

 lections of the Harriman expedition, most of 

 which are well illustrated, but it is prcfbable 

 that a complete collection would considerably 

 increase this number, these animals being re- 

 markably abundant on the Alaskan coast. 



The remainder of the volume is devoted to 

 a report on the littoral Pycnogonidse of the 

 west coast of North America by Mr. Cole. 

 This covers a field almost entirely new to the 

 literature. Twelve species are described and 

 profusely illustrated, of which one is circum- 

 polar and two others are probably evolved 

 from circumpolar types. The list simply in- 



