428 Reviews — Palceontographical Society's Monographs. 



known forms of Vertebra fa. The shields of these old fishes are 

 certainly most unlike the ordinary Ichthyic type, and several (as 

 Cephalaspis, AucJmiaspis, JDidymaspis, and Thyestes) have a mimetic 

 resemblance to the head -shields of those remarkable Palaeozoic 

 Crustacea, classed by Mr. Woodward in the order Merostomata. But, 

 examined microscopically, the shield is found to be composed of 

 three layers, the innermost layer having numerous minute osseous 

 lacunce and canaliculi, whilst large vascular canals traverse it very 

 obliquely in their course towards the middle layer ; this is covered 

 by a close superficial network of vessels, and is permeated by 

 vascular canals ; the outer layer appears structureless, or (like 

 enamel) to be made up of minute fibres. Such a structure as this is 

 wholly unlike that of any known Crustacean. 



Several genera of the Cephalaspidce. have been referred to other 

 classes. One {Archmoteuthis dunensis) having been referred to the 

 Cuttle-fishes, another i^Steganodictyum cornuhicum) to a sponge ! etc., 

 etc. 



Mr. Lankester thinks the mouth of Pteraspis wsls, destitute of teeth, 

 and that it was probably suctorial in form. He places Scaphaspis, 

 Cythaspis, and Ftera.spis, in the Heterostracous section, and Cepha- 

 laspis, Auchenaspis, Didtjmaspis, and Thyestes, in the Osteostracous sec- 

 tion. The five plates which accompany the text are admirably- well 

 and accurately drawn by Mr. Fielding, but there is little beauty for 

 the eye to dwell upon, the chief interest of the specimens consisting 

 in the high antiquity of these Vertebrate remains. 



5. Messrs. W. Boyd Dawkins and W. A. Sanford complete the 

 volume with the second part of their monograph on Felis spelcea. 



Chapter vi. treats of the skull of Felis spelcea, every element of 

 which is most carefully compared and described with the greatest 

 accuracy of detail. Chap. vii. is devoted to the Dentition. Chap. viii. 

 deals with the Vertehrce and the Sternum. Chap. ix. is devoted to 

 the Scapula. Chap. x. to the Humerus. Chap. xi. to the Femur. 

 Chap. xii. to the Tibia, Fibula, and Patella. To each chapter care- 

 fully prepared tables of comparative measurements are appended of 

 all the specimens from the various caverns explored, together with 

 the measurements of the corresponding bones of Felis leo and F. tigris, 

 in the British Museum. The Plates, 14 in number (including nine 

 double quarto size,) are carefully lithographed by Mr. W. Bidgood, 

 of the Taunton Museum, chiefly from drawings made by Mr. W. A. 

 Sanford. The earnest and laborious efforts of both authors to make 

 their monograph as complete as possible, is everywhere apparent, 

 and no one who has not himself worked at comparative anatomy can 

 fully appreciate the amount of hard work which these seven chapters 

 represent. 



Viewed as a mere pecuniary matter, we know of no such a guinea 

 volume in the world as this annual volume of the Pal^ontographi- 

 CAL Society. All who are interested, however slightly, in Geology, 

 should at once join this useful Society, and thus render its power to 

 promote science greater by adding to its means. And, instead of one 

 volume, we may, ere long, receive two annually ! 



