2 26 ARACHNOIDEA. 



CASE -^Yg j^^yg found this species in England about the roots of the 

 vine, along with Phylloxerae, H5rpopi, and Gamasidae. 



Mr. Riley found this curious species in America associated with 

 a Tyroglyphus which he found in the perfect state feeding on the 

 Phylloxera vastatrix at the roots of the grape-vine, and he sup- 

 posed it possible that it might in some way be related to these 

 Tyroglyphi, because in studying their habits he had frequently 

 filled vessels with vine roots from which all but Tyroglyphi and 

 Phylloxera had, to all appearance, been carefully excluded, only 

 to find, on subsequent examination, a number of these mussel- 

 like Hoplophoras, and a corresponding decrease in the number 

 of Tyroglyphi. It is not unlikely, however, that he is in error in 

 this. Our woodcut of the larva of Hoplophora shows how similar 

 they are to the larvae of the Tyroglyphs, and how easy it would 

 be, in sweeping in a number of Tyroglyphs of all ages, unwit- 

 tingly to include some of the larvae of Hoplophora among them. 

 Mr. Riley, however, remarks that from his results happening in 

 the fall of the year, he could not help suspecting that the former 

 might prove to be a hibernating form of the latter ; but with wise 

 discretion he has preferred to explain the facts by supposing that 

 at first the Hoplophora were buried, and consequently invisible 

 within the roots examined, and that the decrease in the number of 

 Tyroglyphs was owing to death and other causes-^an explanation 

 which (says he) is all the more plausible from the fact that he sub- 

 sequently found the same narrow-bodied Hoplophora swarming in 

 decaying cotton wood logs — an explanation, however, which does 

 not meet the circumstance he mentions, that the new Hoplophorae 

 corresponded in number to the missing Tyroglyphs, although it 

 might be sufficient had no such correspondence been observed. 



The present species differs from the other members of the genus 

 in the form of its chitonous coat, which is so narrow that the 

 animal topples over on its side the moment the limbs are with- 

 drawn. 



