18 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



has so admirably expressed as above, will at least be preferred by those 

 who set as much store upon the habits and functions of the creatures as 

 upon their forms. The latter indeed will not be undervalued by a wise 

 and careful student; but the systematists and anatomists will doubtless 

 bear with those w r ho would fain keep natural history from swinging too 

 far away from the paths which earlier naturalists trod, and which so 

 thoroughly traversed the life history of created things. 



A general classification based upon the spider's behavior, especially in 



relation to its chief function, has the advantage that it compels attention 



to the creature's habit without at all neglecting its structure. It 



Fhe Clas- j g no j. claimed that this classification is without objections. There 



sification j j *. i i i -n 



j t'fi d are ' m de e d, some incongruities, more or less serious, which will 



appear hereafter. But until these interesting animals shall have 

 received from naturalists that attention which their character and impor- 

 tance in nature justify, and which will enable some future arachnologist to 

 show us a better way, we shall, perhaps, be best repaid by accepting this 

 general grouping of the great families of the spider fauna. At least it is 

 that which best serves my own purposes in the special lines marked out 

 for this treatise. 



Students who are interested in a more thorough consideration of this 

 point will find the objections to the above system well stated, and a classi- 

 fication proposed based more upon anatomical structure, by Dr. Philip 

 Bertkau, of Bonn. 1 A very satisfactory answer to these objections has 

 been published by Prof. Tamarlan Thorell, M. D., 2 who adheres substan- 

 tially to his former system but, confessing his indebtedness to Prof. Bert- 

 kau for certain modifications, proposes a rearrangement which, he thinks, 

 answers to our present knowledge of this order, as follows : 



ORDO ARANEJE. 

 SUBORDO I. TETRAPNEUMONES. 



Tribus I. Territelarise. 

 SUBORDO II. DIPNEUMONES. 

 Tribus II. Tubitelarise. 

 Ecribellatae. Cribellatse. 



Tribus III. Retitelariae. 

 Tribus IV. Orbitelaria3. 

 Cribellatse. Ecribellatae. 



Tribus V. Laterigradse. Tribus VI. Citigradae. Tribus VII. Saltigrada?. 



The scheme embraces European families for the most part, but includes 

 a few exotic ones. 



1 See especially his " Vereuch einer natiirlichen Anordnung der Spinnen," in Archiv fur 

 NatuivfsrhirliU', xliv., i., page 351, sq., 1878; and his treatise "Ueber das Cribellum mid Cala- 

 inistniiii. Ein Beitrag zur Histiologie, Biologic, und Systematik der Spinnen," ibid., xlviii., i. 

 page 316, et eeq., 1882. 



2 Annals and Magazine Nat, Hist., Apl., 1886. "On Dr. Bertkau's Classification of the 

 Order Aranese or Spiders," by Prof. T. Thorell. 



