cliv GENERAL SUMMARY OF SCIENTIFIC AND 



Among insects, the most important systematic work per- 

 haps that has appeared during the year is an essay on the 

 classification of the weevils (lihyncliophorci) by Dr. Leconte, 

 published in the American Naturalist. He regards this ex- 

 tensive group of Coleoptera, usually mentioned as a sin- 

 gle family, as susceptible of division into three series, each 

 divisible again into a number of families. A good many new 

 moths, Neuroptera, and other insects, have been described in 

 this country, and European journals and transactions teem 

 with diagnoses of new forms of all orders. 



Coming now to the Vertebrates, we have a paper, of which 

 an abstract has been published by Mr. Balfour, on the em- 

 bryology of sharks. He makes the statement that the nerv- 

 ous system is developed from the inner germ-layer, instead 

 of the outer, as in all other vertebrates so far as known. 

 This discovery will throw further doubt on the value of 

 Haeckel's " Gastrcea" theory. 



According to Professor Semper, the embryos of the rays 

 and sharks have segmentary organs like those of the anne- 

 lides. Vo2;t regards this fact as a further indication of a re- 

 lationship between the vertebrates and invertebrates. 



The genus Ceratodus, which was formerly supposed to have 

 become extinct at the close of the Triassic period, but which 

 was a few years ago, to the astonishment of all naturalists, 

 found to be represented by living allies in Australia, lias 

 lately had a new addition (C. JPalmeri) made to it from the 

 alluvial deposits of Queensland. The species is larger than 

 its living relations. This discovery goes a short (and very 

 short) way toward filling up the great chronological gap 

 which intervenes between the extinct European species and 

 the living Australian ones. 



Dr. Giinther has recently examined a considerable collec- 

 tion of the remains of tortoises found in the islands of Mau- 

 ritius and Rodriguez, associated with the bones of the dodo 

 and solitaire, and has arrived at the following conclusions : 



1. These remains clearly indicate the former existence of 

 several species of gigantic land-tortoises, the Rodriguez spe- 

 cies differing more markedly from those of the Mauritius 

 than these latter among themselves. All these species ap- 

 pear to have become extinct in modern times. 



2. These extinct tortoises of the Mascarenes are distin- 



