May 5, 1904] 



NA TURE 



Academy last to hand. In one Mr. J. A. G. Rehn continues 

 his survey of the American bats, dealing in this instance 

 with the genus Dermonotus (Pteronotus), a close ally of 

 Chilonycteris, which, as already noticed in Nature, formed 

 the subject of his preceding article. Of the other two 

 papers — both by Mr. H. W. Fowler — one is devoted to the 

 description of berycoid fishes, and the second to certain 

 fresh-water fishes from various parts of the United States. 



The presidential address to the Indiana Academy for 1902, 

 which is only just to hand, in the Proceedings of that body, 

 is devoted to a survey of the rise and progress of science in 

 Indiana, which date practically from the conclusion of the 

 war of secession. Special attention is devoted to the benefits 

 conferred by science on agriculture, and it is pointed out 

 that, as the result of these investigations, farmers in 

 Indiana will eventually grow only such crops as are best 

 suited to local conditions, and therefore the most re- 

 munerative. 



The second part of the first volume of Records of the 

 Albany Museum contains five notes by Dr. R. Broom on 

 South African anomodont reptiles. In one of these he dis- 

 cusses the affinities of the pavement-toothed genus Endo- 

 thiodon, which was placed by Mr. Lydekker among the 

 dicynodonts, but transferred by Prof. Seeley to the therio- 

 donts. The new evidence demonstrates that the endothio- 

 donts are so closely related to the dicynodonts that it is 

 doubtful whether there is any cranial difference between the 

 two groups, except the presence or absence of the palatal 

 teeth. 



An excellent specimen of modern American zoological 

 work is presented in a long and copiously illustrated article 

 on the " Phylogeny of Fusus and its Allies," by Mr. A. W. 

 Grabau, published in vol. xiv. of the Smithsonian Miscel- 

 laneous Collections. The shells of gastropods, when com- 

 plete, are admirably adapted for phylogenetic study, since 

 they display the whole growth — from the protoconch on- 

 wards — externally. The characters of the protoconch are 

 found to be of prime importance in the group in question, 

 although these must be correlated with the structure of 

 the adult shell. One of the most important results of this 

 line of investigation is the discovery that the genus Cyrtulus, 

 represented by a single species from the Pacific, instead of 

 being inseparable from the Eocene Clavilithes, forms a 

 perfectly distinct type. The well known shells from the 

 Barton Eocene commonly designated in geological works 

 Fiisus longaevus are shown to indicate at least three specific 

 types of Clavilithes, one of which is regarded as new, under 

 the title of C. solanderi. 



The periodic growth of scales as an index of age in the 

 various members of the cod family forms the subject of a 

 very important paper by Mr. J. S. Thomson in the first 

 part of vol. vii. of the Journal of the Marine Biological 

 Association. It has long been known that such growths 

 are annual in the carp, and it is therefore probable that 

 the same holds good for salt-water fishes. So far as can 

 be determined by observation and experiment, this induc- 

 tion appears to be well founded in the case of the Gadid^e, 

 and the author is of opinion that, after making all due 

 allowance for individual variation, the age of these fishes 

 can be determined by the number of rings (not the smaller 

 lines) in their scales. Labelling of individual fishes re- 

 turned to the sea, after their scales have been examined, 

 would afi'ord definite proof of the truth (or otherwise) of 

 the theory. The paper is illustrated with a number of 

 excellent plates. 



NO. 1 801. VOL. 70] 



The March number of the Quarterly Journal of Micro- 

 scopical Science contains an important paper on the dermal 

 fin-rays (dermotrichia) of fishes, by Mr. E. S. Goodrich, of 

 the Oxford Museum. Such structures may be divided into 

 three types. In the sharks and chimaeras these rays 

 (ceratotrichia) are unjointed and composed of a fibrous horn- 

 like substance devoid of bone-cells, and unconnected with 

 the placoid scales found in the skin. In Teleostomi (bony 

 fishes and ganoids), on the other hand, we find small un- 

 jointed, horny rays (actinotrichia) on the edges of the fins, 

 which are probably remnants of the ceratotrichia, and, in 

 addition, branched, bony lepidotrichia, developed externally 

 to the actinotrichia, and in primitive forms closely re- 

 sembling the body-scales. They are probably derivatives 

 from scales which once clothed the fins. Finally, the lung- 

 fishes have jointed, bony rays (camptotrichia) containing 

 bone-cells, and probably representing the lepidotrichia of 

 the teleostomes. In the same issue the editor. Prof. E. 

 Ray Lankester, re-publishes his " Encyclopedia " article 

 on the Arthropoda, one reason for this being that it may 

 readily come under the notice of foreign naturalists. Our 

 readers may be reminded that tlie author considers the one 

 great feature uniting chaetopods, rotifers, and arthropods in 

 a common group is the presence in each body-ring of a 

 pair of hollow appendages — ^paropodia — moved by intrinsic 

 muscles and penetrated by blood spaces. 



Attention was directed in Nature (May 17, 1900) to 

 an article by Mr. Lester F. Ward on the " Petrified Forest " 

 of Arizona, and reference was then made to the presence of 

 a petrified trunk which formed a " natural bridge " across 

 a canyon. We have now received an article by Prof. Oscar 

 C. S. Carter on " The Petrified Forests and Painted Desert 





Fig. I.- : Milt il iree trunk, iii feet long, spanning 



,inir ii, Arizona. 



of Arizona " {Journ. Franklin Inst., April), and this con- 

 tains a number of illustrations of the scenery, including the 

 natural (agate) bridge, which we. are enabled to reproduce. 

 The silicified trunks of trees are considered to i » of Triassic 

 age, and most of them are relics of the denudai'on of the 

 strata; that represented in the natural bridge is, however, 

 in situ. The " Painted Desert " is so named on account of 

 the bright colours of the sandstones, shales, and clays — 

 the rocks being eroded into fantastic shapes, and being 

 coloured blue, yellow, red or green in places ; hence the 

 effect in sunlight is brilliant. An illustration is given of 

 pictographs made by cliff dwellers on a face of sandstone 

 near the petrified forest. The silicified tree trunks mostly 

 belong to forms allied to the Norfolk Island pine (Arau- 

 caria) ; other masses resemble red cedar. There are indi- 

 cations that the wood had commenced to decay before it 

 was silicified. Prof. Carter believes that the petrifaction 

 took place in the sandstone and shale, and was due to 



