54 The American Naturalist. [January, 



" All the great groups of silicious sponges do not figure in this as- 

 semblage, but the fauna presents this character worthy of note, that 

 the Lithistidse and the Hexactinellidse, that is to say, the sponges which 

 have the most complex skeleton occupy a prominent place. 



" I have called attention to these Cambrian sponges to show that 

 there is no fundamental difference between the Precambrian and the 

 Cambrian sponge fauna. In the one as in the other, we find already 

 traced, the lines along which the future silicious sponges are devel- 

 oped." (Annales Soc. Geol. du Nord T., XXIII, 1895.) 



Embryology of Diplograptus.— A large collection of specimens 

 of Graptolites found near Dolgeville, N. Y., furnishes Mr. R. Ruede- 

 man the data for a paper on the mode of growth and development of 

 the genus Diplograptus. The species, D. pristis Hall, and D. pristini- 

 formis Hall, appear as compound colonial stocks instead of single 

 stipes, as hitherto known. From his observations the writer infers 

 that the colonial stock was carried by a large air bladder, to the 

 underside of which was attached the funicle. The latter was enclosed 

 in the central disc, and this was surrounded by a verticil of vesicles, 

 the gonangia, which produced the sicula3. Below the verticil of gon- 

 angia and suspended from the funicle was the tuft of stipes. 



It is evident from the structure of these graptolites that the genus 

 Diplograptus has the combined properties of different groups, and 

 gives valuable hints in regard to their common ancestry. The inves- 

 tigation of Mr. Ruedeman is one of the most important recent acquisi- 

 tions of paleontologic embryology. (Am. Journ. Sci., 1895, p. 453.) 



The Upper Miocene of Montredon. — M. Ch. Deperet has just 

 published the results obtained through the excavations he has been 

 making in the hill of Montredon near Bize (Aude), The fossils which 

 he has collected are found also in the peat beds where they are much 

 broken and slightly worn, and in the white marls where he has found 

 more complete specimens, such as skulls and parts of limbs with the 

 bones in proper relation. 



Notwithstanding an abundance of fossils, the fauna of Montredon, 

 until now, was characterized by a paucity of species, comprising only 

 Dinotherium, Hipparion, a Rhinoceros and an undetermined Ruminant. 

 The discoveries of M. Deperet have increased the known vertebrates to 

 twelve. There are, in addition to the animals just mentioned, a wild 

 >, Tragocem* 





