176 Renews — Dr. E. Fraas — Head-spines of Hybodonts. 



primigenius, Bos longifrons, Cervus elaphus, Capreolus caprcea, 

 Rangifer tarandus, Sus scrofa, and the so-called Sus palustris. A 

 word of warning is also added concerning Cetacean bones, which 

 have often been introduced by man as ornamental gate-posts, and 

 have sometimes been regarded as fossils — even ascribed in error 

 to the mammoth. Ornithology, as may be expected, occupies the 

 greater part of the volume, and comprises nothing of palaeonto- 

 logical significance ; but the final sections on Reptilia, Amphibia, 

 and Pisces are concerned more with extinct than with living forms. 

 The most important reptile-bearing stratum is the Lower Lias of 

 Barrow-on-Soar, which has yielded Ichthyosaurus communis, I. Cony- 

 bearei, I. inter ■medius, I. tenidrostris, I. latifrons, and Plesiosaurus 

 macro cephalus, besides more doubtful species of the same genera. 

 The fine example of Ichthyosaurus showing the pectoral fin will 

 especially be remembered (Geological Magazine, 1889, p. 388). 

 The Barrow quarries, moreover, yield fishes, among which are 

 recorded Mesodon liassicus, Pholidophorus Hastingsice, P. Strick- 

 landi, Heterolepidotus serrulatus, Ptycholepis minor, Dapedius dorsalis, 

 D. monilifer, D. orbis, D. striolatus, Cosmolepis Egertoni, Chon- 

 drosteus, Acrodus, and Hybodus. Belonorhynchus acutus is also 

 ascribed to the same locality, but the original specimen does not 

 exhibit the ordinary physical characters of a Barrow fossil. To 

 the Rheetic beds of Leicestershire are assigned Ceratodus latissimus, 

 Pholidophorus nitidus, Sargodon (?) tomicus, Gyrolepis Albertii, 

 Saurichthys acuminatus, Acrodus minimus, Hybodus cloacinus, Hy- 

 bodus minor, and Nemacanthus monilifer. Acrodus Jceuperinus is . 

 represented by a spine and teeth from the Upper Keuper ; Strophodus 

 magnus, Asteracanthus ornatissimus, and Hybodus crassus occur in 

 the Lower Oolites of Rutland ; and there are several typical Coal- 

 measure scales and teeth from the Ashby-de-la-Zouch Coal-field. 

 Mr. Montagu Browne is still pursuing with success the palaeon- 

 tological aspect of the subject, as shown by the Addenda and more 

 recent publications ; and it may be hoped that in the next edition of 

 the present work a considerable advance in our knowledge of the 

 Vertebrate fossils of Leicestershire and Rutland will constitute one 

 of its most striking features. 



IY. — " KOPFSTACHELN VON EtBODUS UND ACRODUS, SOG. CeBATODUS 



heteromorphus, Ag." By Dr. Eberhard Fraas. Wurtt. 

 Jahreshefte, 1889, pp. 233-240, pi. v. figs. 9-13. 



THE heads of Hybodus and Acrodus discovered in the English 

 . Lias usually exhibit two laterally-placed pairs of hook-shaped 

 spines, fixed upon broad, triradiate bases. These prove that the 

 remarkable Triassic and Rhastic fossils commonly described as Cera- 

 todus heteromorphus are not Dipnoan teeth, but the cephalic spines 

 of Hybodont sharks. Dr. Fraas makes known the various forms of 

 these spines met with in Wiirtemberg, giving some figures, and 

 proposing a definite nomenclature. Some are theoretically assigned 

 to various species of Hybodus and collectively named Hybodonchus ; 

 while others are similarly assumed to belong to Acrodus, and thus 



