96 THE NAUTILUS. 



NOTICES OF NEW PUBLICATIONS. 



DESCRIPTION D'UNE NOUV. ESPECE DE MODIOLA (Feuille des 

 Jeunes Naturalistee, May-June, 1895), M. gallica, Dautzenberg, from 

 the ocean coast of France. 



ON THE VALIDITY OF THE GENUS MARGAEITANA. By Charles 

 T. Simpson (Amer. Nat., April, 1895). The author maintains that 

 Margaritana is not a natural genus, but is of polyphyletic origin, 

 the species having arisen from various diverse groups of Uniones. 



SCIENTIFIC RESULTS OF EXPLORATIONS BY THE U. S. FISH 

 COMMISSION STEAMER ALBATROSS. Report on Mollusca and Brach- 

 iopoda dredged in deep water chiefly near the Hawaiian Islands, with 

 illustrations of hitherto unfigured species from Northwest America. 

 By William Healey Dall. Eight hauls of the dredge were made 

 by the A Ibatross in between 300 and 400 fms., on approaching Hon- 

 olulu, securing a number of very interesting new forms of the genera 

 Scaphander, Pleurotoma, Mangilia, Spergo (a new group) Polinices, 

 Solariella, Emarginula, Dentalium, Euciroa, Lyousiella and Pectun- 

 culus. The anatomy of Euciroa, Halicardia and a new Lyonsiella 

 is discussed by Dall at some length, and the important point that 

 the foliobranch type of gill exists in certain members of groups in 

 which most genera have the reticulate type, is brought forward and 

 amply fortified by figures. Moreover, the branchial septum is shown 

 to be of diverse origin in some allied genera, being made up in part 

 of a reflected nephridial lamina in Halicardia and Lyonsiella. The 

 facts developed tend strongly to break down the primary division 

 of Lamellibranchiata based upon the modifications of the gill, as in 

 the classification of Pelseneer. Euciroa is shown to be different 

 from Yerticordia, of which it had formerly been considered a sub- 

 genus, and a new family, Euciroidce, is formed for it. In gill struc- 

 ture it seems to be intermediate between the foliobranchiate and the 

 reticulate types. " The discovery of this type may be said to prac- 

 tically complete the series uniting the foliobranch with the reticu- 

 late gill, and give the quietus to the classification based solely on 

 the divergencies of the ctenidia." 



The examination of the soft parts of Mytilimerin fle.rnosa shows 

 that form to constitute a new genus now described as Halicardia. 



The second part of the paper gives additional information on 

 Northwest American species of Buceinum, Chrysodomus, Trophon, 

 etc., described in Proc. U. S. Nat. Mus., 1891, with good figures 

 of many interesting forms. A valuable essay on the north Pacific 

 Brachiopods concludes the article. 



