239 



sexes communicated by Cambridge, to this variety. — As a distin- 

 guishing mark between the forma principalis of X. eristatus and its 

 variety (i or pint, may be considered the different form of the wedge- 

 shaped dark middle-spot on the pars cephalica; this spot is in the 

 chief form of the species gradually narrowed behind and reaches 

 with its pointed extremity behind the centre of the cephalothorax , 

 whereas in the Var. /S it is shorter, not reaching to the middle of 

 the cephalothorax, and more shortly and abruptly pointed behind. 

 — Thorn, einereus Blackw. (Spid. of Gr. Brit., I, p. 74, PI. IV, fig. 

 43) is unknown to me. 



Blackwall's Thom. eristatus, judging from his description of the 

 male's palpi (his figures of these organs in the species before us 

 give but little help in the determination of species) , is the same as 

 Westring's Th. eristatus, of which I have moreover, through the 

 kindness of the Rev. Mr Cambridge, received specimens from England 

 under the name af Th. eristatus Blackw. 



The spider figured in Hahn's Monogr. Aran., 6, Tab. 1, fig. C 

 under the name of Thom. eristatus, is an entirely different species, 

 and certainly does not belong to the genus Xysticus. — That A'. 

 eristatus (Clerck) is one of the species confounded by Walckenaer 

 under his Thom. eristatus, is not indeed certain, but highly prob- 

 able. The description he gives (H.N. d. Ins. Apt., I, p. 522) of the 

 sexual organs, must however have been derived from a totally dif- 

 ferent and to me unknown species. He had previously, in Faune 

 Franc. , Arachn., p. 83, taken up "Th. lituratus" as a separate species, 

 but in H. N. d. Ins. Apt. he places it among the synonyms of his 

 Th. eristatus. This 77i. lituratus, which he considers identical with 

 Ar. lituruta Fabr. (Ent. Syst., II, p. 416) cannot be with certainty 

 aggregated either to X. eristatus or to X. Kochii (X. viaticus C. Koch). 

 Among the names given by Walkenaer as synonyms of his Thom. eri- 

 status, Thom. ulmi Hahn and Thom. sabulosus id., to which we shall 

 presently return, belong to species entirely distinct both from X. 

 eristatus (Clerck) , and from X. viaticus C. Koch. Neither does Thom. 

 Clerekii Sav. et Aud. ') appear to me to be same spider as X. eristatus ; 

 different from this latter species are also Aranea notata Linn. 2 ) — 

 which is identical with Theriol. sisyphium (Clerck) — , Ar. atomaria 

 Panz. 3 ) and Ar. (Thom.) fucata Walck. 4 ), which Sundevall (loc. cit.) 



1) Descr. de l'Egypte (2<i« Edit.), XXII, p. 398; Atlas, Arachn. , PI. VI, fig. 13. 



2) Syst. Nat., Ed. 10, I, p. 621. 



3) Fauna Ins. Germ., 74, 19. 



4) Faune Par., II, p. 232; Faune Franc., Arachn., p. 72. 



