Classification of the Spiders. 311 



Spiders are in general divided. I think these tribus are ajj- 

 j)roximately of the same systematic value, and this, if true, 

 is quite sufficient. An exception may, however, be made for 

 the Territelaria3, which really differ from the other tribus by 

 characters of much greater importance than those which 

 distinguish the otlier tribus from each other ; they form a 

 group that may, with almost equal reason, be regarded as 

 coordinate with all the other tribus taken together, as with 

 each of them. However, since Holmberg* and Bertkau 

 (A^ p. 361) have shown that Catadysas-pumilus^Yl^wiZj^wXixch. 

 Hentzf classed with the Territelarise, although this spider has 

 only two air-sacs, cannot belong to that tribus (it belongs 

 probably, as Holm berg thinks, to Zora or to an allied genus), 

 and that Plentz's description and figures of the mandibles and 

 maxillae of Catadi/sas must be erroneous, tlie most important 

 reason for regarding the Territelarias as a group of only 

 about equal value with the other tribus, and as united with 

 the other spiders by transition-forms, no longer exists. 

 They now show themselves to be very sharply distinguished 

 from all other spiders, and I do not hesitate to admit that they 

 may be considered a group of higher rank than the others, 

 which in their turn may be united into a group of the same 

 dignity. For these higher groups or suborders, the old La- 

 treillian names Tetrapneumones and Dipneumones may be 

 readopted. The suborder Dipneumones, then, would consist 

 of the six tribus Orbitelariaj, Eetitelariaj, TubitelarijB, Lateri- 

 grada?, Citigrad^e, and Saltigrada^ ; the suborder Tetrapneu- 

 mones, on the contrary, consists as yet only of one such group, 

 the Territelaria3, from which, however, the Liphistioidai might 

 perhaps be separated and made the type of a separate tribust. 

 When Bertkau says that " the family Theraphosoidte alone 

 shows nearly all those diversities that have been observed within 

 the Tristicta " {A, p. 361), this is, no doubt, an exaggeration ; 

 I cannot find that within the whole suborder Tetrapneumones 

 there exist such widely dissimilar forms as, for instance, Gas- 

 teracatitha and Attus, or Ulcsanis and Pholcus. But that the 

 Theraphosidee, Auss., ought to be divided into 's,Q,Yexix\ families ^ 

 there is no doubt whatever §. 



* "Observations a propos du sous-ordre des Araignees Territelaires (Ter- 

 ritelarife), specialement du genre Nord-americain Catadysas, Hentz, et de 

 la nouvelle t'amille Mecicobothrioid;e," in Boletin de la Aeademia Nacioual 

 de Ciencias en Cordoba (Repiiblica Argentina), iv. p. 153 (188:2). 



t " Descriptions and figures of the Araneides of the United States,'' in 

 Boston Journal of Natural History, vi. p. 287, pi. x. fig. IG (1850). 



X Compare Thorell, " Studi t^ui Ragni Malesi e Papuani. IV. Ragni dell' 

 Indo-Malesia," in Annali del Museo Civico di Storia Naturale di Geuova, 

 xxiii. (ser. 2, iii.), 1886 (iu the press). 



§ See Thorell, ibid. 



