120 NATURAL SCIENCE. Feb., 



zones, " chiefly on north and south lines running across the isocrymes, 

 in accordance with the general trend of the great continental shores." 

 So far, however, as crustaceans are concerned, the inconsistency is, 

 perhaps, less the fault of Dana than of nature, which is for ever 

 interfering with our methodical arrangements. It spoils in various 

 ways the neat simplicity of zonal distribution. The isocrymal lines 

 themselves are far from being exactly parallel. Beneath the warmest 

 surface-waters there are temperate and frigid areas, of which species 

 may, and sundry of them certainly do, avail themselves, to pass 

 from zone to zone across the tropics. The commerce of mankind, as 

 shown in Professor Catta's well-known paper, may help to distribute 

 Crustacea in various directions, as well between north and south as 

 between east and west. As Giesbrecht says in regard to the 

 Copepoda, the arrangement of the fauna by latitude is much more 

 favoured by the waters of the southern hemisphere than by those of 

 the northern. Mr. Faxon seems surprised that Miers and Henderson 

 in their " Challenger " Reports should have followed Dana's method. 

 Obviously they did so simply because the facts relating to the 

 Bracbyura and to the Macrura anomala, so far as they knew them, 

 agreed with Dana's plan. But Miers safeguards himself by observing 

 that the researches of naturalists are always adding to the number of 

 species common to the Indo-Pacific, Atlantic, and Occidental regions. 

 Henderson declares that " the Atlantic and Indo-Pacific regions 

 stand clearly apart from one another, each containing many species 

 with a wide range of distribution, though, if the deep-water forms be 

 excluded, a comparatively small number are common to both." 

 Darwin, though unable to fit the cirripedes into Dana's scheme of 

 distribution, nevertheless maintains on his own account that " the 

 east and west coasts of the two Americas form two quite distinct 

 cirripedial provinces " (" Balanidae," p. 167). These considerations 

 may be allowed to modify, without invalidating, the general proposi- 

 tion that the distribution of marine life accords with the zones of 

 temperature. The arrangement may be compared to a textile fabric 

 in which the warp is closely compact, while the transverse threads of 

 the woof are comparatively, few and scattered. This, indeed, seems 

 to be Mr. Faxon's own view, although in his opening statement he 

 disparages it. 



By pointing out how large a number of littoral species of Crus- 

 tacea in the so-called Panama province closely resemble species in 

 the Caribbean province, Mr. Faxon makes an important contribution 

 to the proof of the theory that, within moderately late geological 

 times, there was water communication between the tropical Atlantic 

 and Pacific. 



A study of the deep-sea Crustacea, Mr. Faxon says, " leads to 

 the conclusion that this fauna is one of cosmopolitan range, indi- 

 visible into subordinate local provinces like those of the littoral and 

 terrestrial faunae." Dr. John Murray has recently remarked that in 

 the " Challenger " results there is " no striking evidence of a 

 universal deep-sea fauna spread all over the floor of the ocean " 

 (Summary, p. 1439), even if there may be an extended distribution of 

 fishes and crustaceans which move freely over the bottom. Mr. 

 Faxon's statement may be applicable to some orders or families of 

 Crustacea, but it is far from having been proved as yet that it is 

 applicable to all of them. 



In the descriptive part of the volume it will be found that the 

 fusion of the families Maiidae and Inachidae, proposed by Miss M. J. 

 Rathbun, is accepted. In addition to this, there is more than one 



