and Systematic Arrangement of British Spiders. 467 



may tend to facilitate a more accurate knowledge of this small 

 but interesting group. 



The Pachygnatha Listen of M. Koch and the Linyphia maxil- 

 losa of M. AValckenaer are evidently the same as Pachygnatha 

 Clerckii ; but the Theridion vernale of M. Hahn and the Pachy- 

 gnatha Listen of Prof. Sundevall, which are included by M. 

 Walckenaer among the synonyma of Linyphia maxillosa, must 

 not be confounded with that species and with each other, Theri- 

 dion remale being identical with the Pachygnatha Degeerii of 

 Prof. Sundevall. As II, AYalckenaer states that the description 

 of his Linyphia Clerckii is borrowed from Prof. SundevalPs ac- 

 count of Pachygnatha Clerckii, I am constrained, notwithstanding 

 the great disparity in size, to regard it as a synonym of the latter. 

 The spider represented bv M. Koch as the Pachygnatha Clerckii 

 of Prof. Sundevall (Die Arachn. 13. xii. p. 146. tab. 430. fig. 1067) 

 is quite distinct from that species, and is admitted to be an im- 

 mature individual by M, Koch himself, who remarks, "Ichfand 

 sie auf einer Reise in der Nahe von Zweibriicken, aber nur Weib- 

 chen und diese nicht im Zustande vollstandiger Ausbildung ; ein 

 solches stellt die hier gegebene Abbildung vor." 



Mr. T. Blackwall met with Pachygnatha Clerckii, which pairs 

 in October, under stones and rubbish in the township of Crump- 

 sail, in the autumn of 1831 ; and I have since received specimens 

 of it from Yorkshire and Middlesex. In it are combined several 

 striking characteristics of the species composing the genera The- 

 ridion and Tetragnatha. Allied to the former by the structure 

 of the oral apparatus, and by the irregularity of the insignificant 

 web it fabricates, it resembles the latter in the form and relative 

 length of its legs, which it frequently extends in the same manner 

 as Tetragnatha extensa ; thus closely connecting the Theridiida 

 with the Ep'e'irida. 



181. Pachijgnatha Listeri. 



Pachygnatha Listeri, Sund. Vet. Acad. Handl. 1829, p. 210. 

 Mandnculus limatus, Blackw. Linn. Trans, vol. xviii. p. 667. 



The Linyphia mandvcula of M. Walckenaer (Hist. Nat. des 

 Insect. Apt. t. iv. p. 482) is the same as Manduculus limatus, and, 

 consequently, lapses into a synonym of Pachygnatha Listeri. 

 This species occurs under stones and on bushes in woods about 

 Oakland, and the male has the palpal organs completely de- 

 veloped in September. It has also been captured in Lancashire 

 and Yorkshire. 



In the 'Transactions of the Linnsean Society/ vol. xviii. p. 668, 

 it is proposed to institute a comparison between Manduculus 

 limatus and the Linyphia ienebricola of M. "Wider (Museum 

 Senckenbcrgianum, B. i. p. 267. taf. 18. fig. 2) ; as they differ, 



