38 TERRESTRIAL CARBONIFEROUS ARACHNIDA. 



Genus CURCULIOIDES, Buckland. 



1837. Curculioides, W. Bucklancl, Bridge-water Treatise (ed. 2), vol. ii, p. 76 (iu part, G. ansticii). 



1902. Curculioides, E. I. Pocock, Geol. Mag. [4], vol. ix, p. 439. 



1890. Geratarbus, S. H. Scudder, Mem. Bost. Soc. Nat. Hist., vol. iv, p. 447 (iu part, G. scabrum). 

 1890. ? Kustarachne, S. H. Scudder, Mem. Bost. Soc. Nat. Hist., vol. iv, p. 450. 



1903. Kustarachne, A. L. Melander, Jouru. Geol. (Chicago), vol. si, p. 181. 



The genus Curculioides was based by Buckland on two fossils in ironstone 

 nodules from Coalbrook Dale, which this author regarded and described as 

 Coleopterous insects. One of these was named G. ansticii, the other G. prestvicii. 

 The latter was subsequently made the type of Eophrynus by Dr. Henry Woodward, 

 who thus fixed C. ansticii as the type of Curculioides. In 1884 Scudder suggested 

 that G. ansticii was an Arachnid related to Archikwbus. I, on the contrary, 

 suggested that it was allied to Gryptosteinma, judging solely from the figure of it 

 published by Buckland. The correctness of this surmise and the reasons given in 

 support of it have been confirmed by specimens in Mr. Egginton's and Mr. Madeley's 

 Collections. 



That the Arachnid described by Scudder as Geratarbus scabrum, is closely 

 related to those that I refer to Curculioitles is, I think, indisputable ; but it is 

 equally indisputable, in my opinion, that G. scabrum belongs to a different order of 

 Arachnida from (V. lacoei, which I have fixed as the type species of Geratarbus 

 (Geol. Mag. [5], vol. vii, p. 511, 1910). About Kustarachne there is more room for 

 doubt on account of Scudder's statement that the opisthosoma consists of nine 

 segments, including the short two-jointed "protuberant pygidium." Although 

 none of the specimens I have seen shows distinct signs of abdominal segments, the 

 one in Mr. Madeley's Collection possesses what might be called a " protuberant 

 pygidium," and this process is also Avell exhibited in Buckland's original figure. 

 Nevertheless, it would have been difficult to justify the suggestion that Kustarachne, 

 based upon K. tenuipes, belongs here, were it not that the species described by 

 Melander as K. sulcata seems to be unmistakably akin to the examples in Mr. 

 Ee'2'inton's Collection, which show the ventral side. Melander described K. sulcata 

 as deeply punctured and as being provided with a triangular sessile pygidium of 

 two, possibly three, segments. Apart from this last character the abdomen seems 

 to show no segments. It is possible, of course, that Kustarachne tenuipes and K. 

 sulcata differ generically. Nevertheless, the measurements of the two type 

 specimens agree suspiciously closely, and both came from Mazon Creek, Illinois. I 

 suspect that one shows the dorsal, and the other the ventral view of specimens 

 belonging to the same species. 



