August io, 191 j 



NATURE 



'97 



Museum, Dr. Broom contributes an illustrated article on 

 :he dinosaurs of the Stormberg beds. Seven generic 

 :ypes, namely, Euskelesaurus, Hortalotarsus, Gyposaurus, 

 Jryponyx, Massospondylus, .-Etonyx, and Geranosaurus, 

 are recognised, of which the third, fourth, sixth, and 

 seventh are described for the first time. The first six are 

 referable to the carnivorous group, but the last is charac- 

 terised by the presence of a predentary bone to the mandible. 

 This feature suggests that the horizon of the Stormberg 

 beds from which it was obtained is of Lower Jurassic, in 

 place of Triassic, age ; and, even so, Geranosaurus will be 

 the oldest known type with a predentary. 



The angulated outer and rounded inner surface of the 

 terminal segment of the second hind toe in Gryponyx, 

 Massospondylus, and /Etonyx indicates that the investing 

 horny claw had an edge adapted for combing or scraping ; 

 and it is suggested that it was employed for cleaning the 

 skin and scales. If this be so, the dermal covering was 

 probably unlike that of crocodiles or lizards; and it may 

 be that the scales were long and narrow v"ith intervals of 



Tail-fins of Ichthyosauria. 



Fig. 1. — Mixosaurns notdotiskjoeldi. 



Fig. 2. — Ichthyosaurus quadriscisuts (young). 



Fig. 3. — Ichthyosaurus ouau'riscissus (adult). 

 Fig. 4. — Icllthyosaui us t>iso/ius postlutmus. 



soft bare skin between them. Such a skin would certainly 

 require cleansing with the claw after the reptiles had been 

 hunting on the muddy banks of lakes. 



In the same issue Dr. C. W. Andrews describes portions 

 jf the skeleton of a plesiosaur (Plesiosaurus capensis) from 

 he Uitenhage beds of Cape Colony. The species, which 

 Delongs to the group of small forms represented in the 

 European Wealden by P. degenhardti and /'. valdensis, is 

 :he Erst plesiosaur known from South Africa. The occur- 

 ence of a member of the group in that country is of 

 special interest, in view of the possibility that the 

 sauropterygia may have taken origin from a form related 

 :o the theroccphalous anomodonts of the South African 

 Permian. 



In this connection reference may be made to the identifi- 

 :ation by Mr. H. Fuchs {Anat. ' Auz., vol. xxxviii.) of a 



NO. 2 1 SO, VOL. 87] 



septomaxillary bone in the skull of the peba armadillo. 

 In a review of this discovery by Mr. F. Midler in Natur- 

 wissenschaflliche Wochenschrift for July 9, 1911, it is 

 pointed out that a septomaxillary has been hitherto known 

 in amphibians and certain reptiles, in which it forms an 

 ossicle on the side of the nasal capsule. Recently it has 

 been identified in certain fossil reptiles — notably the Therio- 

 cephala and Theriodontia. Among mammals, it occurs not 

 only in the peba, but likewise in the hairy armadillo 

 (Dasypns villosui), where it is represented by an undeter- 

 mined bone described by Dr. Broom. It has not yet been 

 definitely identified as a separate ossification in other 

 mammals ; but Gaup considers that it is represented by 

 the so-called extra nasal process of the maxilla, although 

 Fuchs considers that in the aforesaid armadillo both this 

 process and the septomaxillary are present. Be this as it 

 may, the identification in armadillos of an element common 

 to amphibians, anomodonts, and certain other reptiles is a 

 feature of prime importance in regard to the anomodont 

 ancestrv of mammals. 



The description of an embryonic, or newly born, speci- 

 men of Ichthyosaurus quadriscissus from the Lias of 

 Holzmaden, Wiirttemberg, in which the outline of the body 

 and fins is preserved, has led Dr. E. Fraas, in Mitt, aus 

 dem kgl. Naturalienkabinett, Stuttgart, to give an 

 interesting account of the evolution of the tail-fin in the 

 ichthyosaurs. That the specimen on which the investiga- 

 tion was based is extremely young is rendered evident by 

 the great relative size of the head, which is equal to one- 

 third the entire length, whereas in the adult it is less 

 than one-fifth. The earliest known type of tail-fin in the 

 ichthyosaurs occurs in Mixosaurns twrdenskjocldi from 

 the Muschelkalk of Spitsbergen, in which, according to 

 Mr. H. Wiman's figure in Bull. Geol. Inst. Upsala, vol. 

 x., 19 10, it takes the form of a low falcate fin in the 

 basal third of the tail, continued as a marginal expansion 

 along the whole of the rest of the tail, both above and 

 below. In the young of I. quadriscissus the falcate por- 

 tion and the marginal fringe are increased in height so 

 as to form a fin approximating to the heterocercal type, 

 with the extremity of the vertebral column bent down into 

 the lower lobe. In the adult of the same species the in- 

 crease in the size of the fin and the degree of flexure of the 

 vertebral column are intensified, thus producing an approxi- 

 mation to the homocercal type. A further stage is dis- 

 played by I. trigoaus posthumus, of the Upper Jurassic 

 Limestone of Soienhofen, in which the fin is almost com- 

 pletely like that of a homocercal fish, while the flexed 

 terminal portion of the vertebral column has diminished in 

 relative size, with a marked increase of the angle of 

 flexure. One step more and it would have vanished. A 

 somewhat similar grade is presented by Opthalmosaurus 

 of the Oxford and Kimeridge Clays. It should be added 

 that in the hind paddle of Mixosaurns the metatarsal and 

 phalangeal bones retain an elongated contour, and do not 

 form a mosaic-like structure. R- L. 



A 



LONG-DISTAXCE RADIO-TELEGRAPHY. 

 VERY interesting paper by Mr. L. W. Austin, 

 entitled " Some Quantitative Experiments in Long- 

 distance Radio-telegraphy," has recently been published in 

 the Bulletin of the Bureau of Standards (Reprint No. 159). 

 The paper describes a complete investigation of the 

 relationship between the current in the receiving aerial 

 and the distance between the transmitter and receiver, the 

 observations being mainly by the shunted telephone 

 method. Although this method is not so accurate as the 

 direct method, it is probably the only one available for 

 use on board ship at long distances. Some years ago Mr. 

 J. E. Taylor and the present writer carried out similar ex- 

 periments over short distances up to 60 miles, using a 

 thermo-galvanometer directly in the aerial. Mr. Austin 

 has greatly extended the range, and has carried on the 

 experiments up to a distance of 1200 miles between the 

 two stations. The results confirm the proposition put for- 

 ward by Mr. Taylor and the writer that the current in 

 the receiving aerial varies inversely with the distance 

 except for one important particular, namely, Mr. Austin 

 finds, with much longer distances that he has worked 



