200 



kins has sliowii, and parallel cases could be drawn from the 

 rest of the fanna and from the flora. If we postulate a con- 

 tinental area to account for the presence of certain land shells 

 and for the absence of others, we confront a vastly greater 

 task to account for the absence of vast oroups of animals and 

 plants. 



Most ])aleogeoi;'rai)hers insist on a larger land area in the 

 Southern Pacific than exists at present and on an extension 

 of the northwestern portion of South America, or the western 

 coast of Central America, in a northwesterly direction. Such 

 land areas would greatly alter ocean currents and increase the 

 probal)i]ities of ''drift" reaching the Hawaiian Islands from 

 those regions. 



Prof. Pilsbry's opposition to the flotsam and jetsam method 

 of stocking islands breaks down considerably when he admits 

 such a method to sto<'k low islands of the Pacific and in such 

 cases as Tornatell'ma in the Galapagos. 



After considering the evidence of the fauna and flora, and 

 of geology and hydi-ography, it appears to me that the theory 

 of the continental nature of the Ilawaiian Archipelago is the 

 less tenable, as it raises greater problems than it is called \\\)0\\ 

 to solve. Therefore in the following Review I shall consider 

 that the Islands are oceanic ; that the fauna is descended from 

 inmiigrants which arrived at different periods, and that the 

 Islands are of enormous antiquity, instead of the alternative 

 continental theory which would make our fauna the descend- 

 ants of continental type which flourished in late Palaeozoic 

 or early ^lesozoic times. 



OiiKiix OK THK Hawaiian Aloiiixi. 



In the systematic portion of this Kevicw it has been shown 

 that the species can l)c divided into two groups. In one group, 

 Leialohae, consisting «>f Lc'udolia and Nesodrym, tlie first joint 

 of the antennae is very short; in the other, Alohae. consisting 

 of Aloha, Nesorestias, Didyopliorodelpliax and Nesosydnc, the 

 first joint of the antennae is much longer. A study of the 

 male genitalia leads to the conclusion that they are of inde- 

 pendent origin and form two distinct phylogenetic groups. 

 The foi'ni of I he acdcagus, the styles and the mechanism for 

 coordinaling ihcii' nioveincnts with that of the anal segment 

 are different. 



