GENERAL CLASSIFICATION AND STRUCTURE. 



The following tabular exhibit is given of this classification, or group- 

 ing, if that word seems to any one more suitable : — 



Class Arachnida. 

 Order Arane^e. 

 I. First Division. — Sedentary Spiders. 

 Tribe 1. Orl)itelaria^,i Orb weavers. Tribe 3. Tubitelarite, Tubeweavers. 



" 2. Retitelari»,2 Lineweavers. " 4. Territelarije, Tunnelweavers. 



II. Second Division. — Wandering Spiders. 



Tribe 5. Citigradse,^ Citigrades. Tribe 6. Laterigrada;, Laterigrades. 



Tribe 7. Saltigrada?, Saltigrades. 



This arrangement is the best, perhaps, that can be adopted, and seems 

 more natural and satisfactoiy than that which commanded the approval of 



such a distinguished arachnologist as 

 Blackwall, and which is based upon 

 the number of the eyes. Blackwall 

 founded three tribes, within which all 

 the species known to him are includ- 

 ed. They are: (1) Octonoculina, eyes, eight ; (2) 

 Senoculina, eyes, six ; (3) Binoculina, eyes, two. 

 In the first tribe, Octonoculina, which is the 

 most extensive of the three, he included all the 

 genera having eight eyes, without regard to 

 other characteristics or to the considerable dif- 

 ferences in organization and economy. The 

 second tribe, Senoculina, as known to Black- 

 wall included but ten or eleven genera, and 

 embraced all tribes having six eyes, with the .same disregard to other char- 

 acteristics. The third tribe, Binoculina, contained the single genus Nops, 

 instituted by Mr. W. S. McLeay for the reception of two remarkable species 

 of extra European spiders.* The Latreillian classification, which Thorell 



Black- 

 wall's 

 Classifi- 

 cation. 



Fig. 3. Laterigrade Spider, Misume- 

 na rosea Keyserling. 



' Araneie Orbitelarise : Perty, Delect. Anim. Art. Bras., page 193. 



^ From retas, a net. The word "net" very well expresses the knotted and meshed char- 

 acter of most spinningwork of this group. But since it is used popularly as a general term 

 for the webs of all spiders, I have preferred " Lineweavers " to " Netweavers " as a dis- 

 tinctive popular name of this tribe. 



^ Prof Thorell assigns the Laterigrades to tlie fifth trilje, the Citigrades to the si.xth. I 

 have ventured to so far change this arrangement as to reverse the positions of the Lateri- 

 grades and Citigrades. The Citigrailes api)car to me to approach the Tunnel weavei-s and 

 Tubeweavers, lioth in structure and economy, more nearly than the Laterigrades. So also 

 the step fi-om the Citigrades to the Laterigrailes tlirough the genus Dolomedes appears more 

 natural than the reverse, as Thoi'ell has it ; and the step to the Saltigrades from the Lateri- 

 grades is quite as, if not more, natural than from the Citigrades. From the standpoint of 

 economy alone the passage is certainly easier. 



' Blackwall, "Spiders of Great Britain and Ireland," Preface, page (>. 



