422 Scientific Intelligence. 



relationships and synchronous variations between the soft and 

 hard parts of the animal. This emphasizes the general truth that 

 the shell is not the mere covering or domicile of the animal, but is 

 a highly specialized enveloping organ, subject to modification 

 from changes in the soft animal within, and to the varying condi- 

 tions of the environment. From the nuculoid prodissoconch, 

 Pecten passes through stages corresponding to Rhornbopteria, 

 Pterinopecten, and Aviculopeoten. 



A genealogical table for the Aviculidse and their allies is 

 proposed as a result of these investigations, based upon fossil 

 and recent forms. A nuculoid shell of Lower Silurian type is 

 taken as the radical. The new genus Rhombopteria is proposed 

 for a group of Aviculoicls of which Avicula mira Barrande is the 

 type. It is considered as the prototype and ancestral form of 

 three distinct branches ; one by direct descent through Leptodes- 

 ma to Avicula, with side branches to Pinna, Perna, Ostrea, 

 Malleus, etc., another doubtful side branch to Pterinea and 

 Ptychopteria, and the third diverging through Pterinopecten and 

 Aviculopecten to Pernopecten, Pecten, Plicatula, Anomia, Pla- 

 cuna, and allied genera. c. e. b. 



2. Revue des travaux de paleontologie vegetate, parus en 1888 

 ou dans le cours des anne.es pr'ec'edentes / par le Marquis Gaston 

 de Sapoeta. Extrait de la Revue generale de Botanique, tome 

 II, Paris, 1890. — This exhaustive review of paleobotanical litera- 

 ture contains much that is original and goes far to settle a large 

 number of the more perplexing problems of the science. The 

 subject is treated by geologic eras, the author's former classifi- 

 cation of Paleophytic, Mesophytic, and Neophytic, being em- 

 ployed. As on former occasions he makes the Mesophytic extend 

 so as to include only the Lower Cretaceous, and the Neophytic 

 to begin with the Cenomanian and include the Upper Cretaceous, 

 this being the point in vegetable paleontology where the most 

 distinct line of demarkation occurs. Among the more important 

 points brought out may be mentioned the following : The great 

 difference between the Paleophytic and Mesophytic ferns and 

 those of modern times ; the acceptance of the cryptogamic nature 

 of Sigillaria and Calamodendron, so long denied by the French 

 school ; the announcement of the discovery of a Lower Creta- 

 ceous flora in Portugal containing dicotyledons, and similar to 

 that of the Potomac formation of Virginia; and the surrender of 

 the much discussed problematical organisms called Spirangium or 

 Palaeoxyris to the zoologists as of animal nature. l. e. av. 



3. JSfotes on the Leaves of Liriodendron ; by Theodob Holm. 

 Proc. U. S. Nat. Mus., vol. xiii, 1890, pp. 15-35, pi. iv-ix, 

 Washington, 1890. — Mr. Holm is making a study of the germina- 

 tion of plants and of the earlier leaves as they appear following 

 the cotyledons. In this paper he has described and figured a 

 large number of these early leaves of Liriodendron Tidipifera, 

 which prove to be very interesting and of special importance to 

 the student of paleobotany, since these early leaves are supposed 



