No. 605] 



NOTES AND LITERATURE 



315 



able that in the ancestral fishes each membrane bone and each 

 scale grew from clusters of cosmine tubercles underlain by tracts 

 of vascular and stratified bony tissue, and that there never was 

 a time when the elements of the dermo-cranium were scale-like 

 in form {i. e., rhombic or polygonal), although the several tissues 

 involved were histologically identical in the body scales and in 

 the dermo-cranium. 



On page 85 the author uses the name "squamosal" for the 

 element which he and most other authorities now designate as 

 "supratemporal." 



In the description of the hyobranchial elements of Coccytinus 

 (a genus doubtfully assigned to the Proteida), the reader looks 

 in vain for a comparison with the same elements in the Permian 

 "Urodele" Lysorophus as described by Williston. It may be 

 noted, by the way, that the branchial arches in that genus are 

 extremely primitive and almost Polypterus-like in form and 

 arrangement, although doubtless homologous also with those of 

 the modern AmUystoma. 



The author has given a very thorough study of the dermal 

 scales and scutes of the branchiosaurs, microsaurs and tem- 

 nospondyls. The ventral ' * scutellae, " which appear to be 

 homologous with the abdominal ribs of reptiles, are formed, the 

 author holds, as ossifications in the connective-tissue septa or 

 myocomata of the ventral muscles, vestiges of these having been 

 found in modern urodeles. The highly differentiated charac- 

 teristics of this ventral armature affords many family and 

 generic characters ; it is sometimes absent or reduced to needle- 

 like ossicles, sometimes highly developed, forming heavy median 

 Vs and wide lateral shelves (Ctenerpeton) . Some of the micro- 

 saurs had rounded, slightly imbricating fish-like body scales 

 with concentric markings which recall the similar armature of 

 certain Bohemian and Saxon types, such as Rlcnodnn and D/,v- 



scales of modem ca^'ilians (as sliown in the enlargeil figures of 

 caBcilian scales by the Sarasin brothers). 



The reviewer ventures to doubt the correctness of Dr. Hoodie's 

 reconstruction of the shoulder-girdle of branchiosaurs and micro- 

 saurs. in the matter of the position of the scapula. Many of the 

 specimens figured by Fritsch and by CrediuM- seem to indicate 



form the gltMioi<l border as in Dr. Moodie's reconstructions. 



