CURRENT LITERATURE. 



AMI'HINEURA 



Cephalopoda is unchanged, and the author's views upon the classification of the 

 Lamellibranchia are already known. There remain the classes Amphineura and 

 Gastropoda, the author's sub-division of which is here appended : — 



i Polyplacophora. 

 t Aplacophura. 



,• I Rhipidoglossa. 



Aspidobranchia I -r» 1 



i t\- a. j- \ " Docoelossa 

 . = Uiotocardia) 



Streptoneura. 



Ctenobranchia ( Platypoda. 



( = Patellid^). 



Gastropoda. < 



: Monotocardia) I Heteropoda. 



Tectibranchia. 

 Nudibranchia. 



V 



I Opisthobranchia. 



Euthyneura. -! 



„ , ( Stylommatophora. 



I Pulmonata. \ Tt J . r , 



^ ( Basommatophora. 



The separation of the Amphineura from the Gastropoda is amply warranted, 

 we think, by recent morphological research. We must also admit that in regarding 

 the ChitonidcC as less modified than the Neomeniidse, and in emphasising the 

 resemblances between the former and a generalised Eunicid type, Prof. Pelseneer has 

 not exaggerated the evidence at his command. Indeed, were there any embryo- 

 logical evidence of an ancestral metamerism of the mesoblast in Mollusca, we 

 should regard the Annelidan origin of the phylum as well established. At present, 

 however, Nautilus alone among Mollusca exhibits a reduplication of the nephridia ; 

 and it is extremely doubtful whether the metamerism of Nautilus has not been 

 secondarily acquired. — W. G. 

 Pilsbry, H. A. — Notes on the Genera of Uriionidce and Mutelidce. Naut., 1S93, 



vii., p. 30. (See Simpson, C. T. ) 

 Pilsbry, H. A. — Notes on the AchanthochitidcB, with descriptions of new 



American species. Naut., 1893, vii., p. 31. 

 Pilsbry, H. A. — Polygyra sub-palliata, n. sp. Naut., 1893, vii., pp. 5-7. 

 Rolle, Hermann, — Eine Neue Pseudoglessula, Nachr. Deutsch. Malak. Gesell., 



1893, pp. 86-7. 

 Simpson, C. T. — A Review of von Jhering's Classification of the Unionida and 



Mutelidce. Naut, 1893, v »-> PP- 17-21. 

 Simpson, C. T. — A Reply to Professor Wheeler. Naut., 1S93, vii., p. 22. 



(See Wheeler, C. Le Roy). 

 Simroth, H. — Kritische Bemerkungen iiber die Systematik der Neomeniiden. 



Zeit. f. Wiss. Zool., 1893, lvi., pp. 310-327. 

 In editing the mollusca for Bronn's " Klassen und Ordnungen," Dr. Simroth 

 has had occasion to review the morphological and systematic work of the 

 Norwegian and Mediterranean naturalists who, at considerable intervals, have 

 investigated the species, between twenty and thirty in number, which compose 

 this family. In this paper he criticises the only existing classification (that of 

 Pruvpt) and attempts a new one, not based, as was Pruvot's, on the variation of a 

 single organ (the gill) but on the combination of a larger number of anatomical 

 features. Accordingly, the author gives an interesting resume of the variations of 

 the form of the body, of the foot, and of the various systems of organs. Coming 

 to Dr. Simroth's classification, we have a division into {a) Northern and 

 {0) Mediterranean forms, a mode of expressing the interesting fact that, as far as 

 our present knowledge goes, the genera under section (a) are in every case distinct 

 from those under (l>). This, however, can only be regarded as a temporary mode 

 of classification. Under (a) the genera Neoweuia, Proneomenia, and Solenopus 

 are re-defined, and are now, as indeed is the case with the genera right through 

 this classification, of very limited extent. Among the Mediterranean forms a 

 number of new provisional genera have been defined — Rhopalomenia, Macelio- 

 menia, Nematomenia, Myzomenia, Echinomenia. These, together with Paraweuia, 



