No. 555] NOTES AND LITERATURE 



185 



is illustrated by various reconstructions of the pterodactyls from 

 Wagler's restoration of Pt< rodactylus in 1830 to Eaton's restora- 

 tion of Pteranodon in 1910. Dr. Abel contends that the recon- 

 struction of a fossil species is valuable, since it gives graphic- 

 ally all that is known of that form at the time the restoration 

 is given. The fact that it may be wrong is no reason why res- 

 torations should be abandoned, since they record the progress 

 of our knowledge of annual tonus. 



Dr. Abel uses as an illustration of the genetic line of descent 

 that of the Cetacea, in which group he is an acknowledged 

 authority. His discussion is illustrated from previous papers. 

 The descent of the whales has been brought about in the reduc- 

 tion of certain structures, such as the teeth and the limbs. As 

 an illustration of a line of descent which has operated in the way 

 of complication of structures he cites the elephant series which 

 has been made well known through the researches of Andrews 

 and Osborn. The reader notes with a sigh of relief that but 

 little attention is given to the line of descent of the horse (" das 

 Paradepferd der Paleontologie "). 



Dr. Abel's selection of the sea turtles as an example of Dollo's 

 law that " A structure once lost or reduced in development of 

 a race is never regained " is timely and refreshing since it has 

 been but little used. He gives Wieland's restorations of 

 Archelon and bases his conclusions on Dollo's researches on the 

 phylogeny of Dermochelys coriacea. He discusses, in the two 

 last sections of the chapter, " Stufenreihen " and illustrates 

 his discussion by Dollo's work on the dipnoan fishes, illustrat- 

 ing forms from the lower Devonian to recent and, in the last 

 section, ' ' Ahnenreihen ' ' he discusses the derivation of the 

 Sirenia and illustrates by the pelvic girdles of the sea cows 

 from the middle Eocene to recent. 



The concluding remarks show a strong desire to further the 

 relation between paleontology and zoology " damit wir mit 

 vereinten Kraften unserem gemeinsamen Ziele, der Aufhellung 

 der Stammesgesehiehte. entgegenschreiten. " In view of the fact 

 that paleontology has been largely in the hands of the geolo- 

 gists this is a relation much to be wished. 



Charles W. Gilmore 1 has described an interesting new form 

 of Alligatoridje from the "Hell Creek Beds" (Upper Creta- 

 ceous) of Montana. Only a portion of the skull was preserved 

 for description. This has been restored into the shape of the 



1 Proc. V. 8. Natl Museum, 41, 297-302, 2 pis. 



