INTRODUCTION. 



On account of the habits of the Attidse they are, in comparison with 

 other families, poorly represented in collections. The most important con- 

 tribution to the knowledge of North American species is the work of N. M. 

 Hentz, his studies having been largely carried on in the southern states. 

 The papers of Hentz were originally published in tlie Journal of the Boston 

 Society of Natural History, from 1842-45, but are found in more convenient 

 form in the collection made by Burgess in 1875. The works of Baron 

 Walckenaer, 1837-47, and that part of Die Arachniden, by C. Koch, pub- 

 lished in 1848, contain discriptions of many American Attidse, but owing to 

 the vagueness of the descriptions comparatively few can be identified with 

 certainty. So far as Koch is concerned tliis is of slight importance, as his 

 w^ork was preceeded by that of Hentz. But with Walckenaer the question 

 of priority comes up, as doubtless many of the species commonly ascribed to 

 Hentz were first published by him, and he should be credited with all such 

 species as can be identified from his descriptions. The important question 

 is, what species can be identified by Walckenaers descriptions? 



We have made a very careful study of the descriptions of Walckenaer's 

 sixty-four species, comparing them with nearly all Hentz's species and 

 with many others from different sources and we have been able to identify 

 only four. 



On the subject of priority we agree with Dr. Thorell that " to reject a 

 name, as some have proposed to do, on account of clef ectiveness in the defi- 

 nition, would seem not to be right, as leaving room for much arbitrariness. 

 What seems to one good enough may to another appear insufficient or faul- 

 ty. When one only knoics icith certainty ichat is to be understood by such 

 a name, every one can either alter or improve the characterization for 

 himself. ' " We wish it to be understood that we reject none of Walck- 

 enaer's species on accoimt of defectiveness of definition. We accept them 

 whenever we are able to identify them. 



Walckenaer's work on North ximerican species was largely based on the 

 manuscript plates of Abbot. He does not, so far as we know, state express- 

 ly tliat he has seen any of the specimens, but that he has examined most 

 of them must be understood from the following statement which he makes 

 before enumerating thirteen species. '" Les especes suivantes n'out pas ete 

 observees par nous, et ne sont placees dans cette section que sur les indica- 

 tions fournies par les figures de I'ovurage MSS. d' Abbot, intitule: Georgian 

 Spiders. " • 



' On European Spiders. I., p. .". The italies in the L-i)neliulin>; sent^-nce ar<- ours. 



