5336 Notices of New Books. 



of a fin will, as a diagnostic character, supersede the great faculty of 

 swimming for which that fin is provided ; whether the form of a 

 maxilla so similar in a grasshopper and a beetle, will be regarded 

 as more worthy of note than those differences of metamorphosis 

 which have been the wonder of the unlearned and the admiration of 

 sages in all ages of the world. 



Mr. Dallas has evidently read up for his task with care and assi- 

 duity, and there is abundant evidence of much book knowledge 

 throughout the volume. There is nothing, however, that displays a 

 practical acquaintance with the subject, except in that portion of the 

 volume devoted to insects, and here Mr. Dallas's knowledge of the 

 things themselves becomes more manifest; but unfortunately he has 

 not the knack of methodizing that knowledge so as to make it easy and 

 agreeable to the student; take, for instance, his general arrangement 

 of Articulate animals : here it is — 



Subdivision 1. Vermes. 



Class 1. Platyelmia [Entozoa]. 



Order 1. Cestoidea. 



Order 2. Trematoda. 



Order 3. Planarida. 

 Class 2. Nematelmia. 



Order 1. Acanthocephala. 



Order 2. Gordiacea. 



Order 3. Nematoidea. 

 Class 3. Annelida. 



Order 1. Suctoria [the leaches]. 



Order 2. Scolecina [earth-worms]. 



Order 2 [3]. Tubicola. 



Order 4. Errantia. 

 Class 4. Rotifera [Infusoria]. 



Order 1. Sessilia. 



Order 2. Nalantia. 

 Subdivision 2. Arthropoda. 

 Class 5. Crustacea. 



Subclass and Order 1. Cirrhopoda. 

 Subclass 2. Entomostraca. 



Order 2. Parasita. 



Order 3. Copepoda. 



Order 4. Ostracoda. 



Order 5. Phyllopoda. 



