20 ME. G. BBOOK ON SOME 



LoBg. 1 mm.;"* and I may add from liis original description, 

 '" Ocelli in macula nigra positi, uuguiculus superior Bine dente, 

 inferior parvus " f. 



In this species the anal spines are not so large as in A.piirpu- 

 rescens, and the papillte on Avhich tliey are placed are very small 

 and further apart than in Lubbock's species. The chief di- 

 stinction, however, lies in the spring. In purpiirescens the manu- 

 Irium is not longer than the denies, and the latter gradually taper 

 off into the mucrones with merely a faint line to show the point 

 o£ union. In 7nanuhrialis, on the contrary, the inamihrium is as 

 long as the denies and mucrones together. The denies do not 

 taper as in purpurescens, but end abruptly in the mucrones, which 

 are slender and convergent. The latter character is useful in 

 helping to distinguish from A. Theelii, Tullb., an intermediate 

 species, which has the mucrones not convergent and the dentes 

 tapering a little more than in manuhrialis, but still witli the 

 point of union between the dentes and mucrones quite distinct. 

 It may be doubted whether, in making such minute differences 

 of specific value, Tullberg is not going a little too far ; but it 

 would be impossible to judge fairly without comparing a large 

 number of specimens. In any case manuhrialis appears to be suffi- 

 ciently distinct from imrpurescens to rank as a separate species. 

 Its body-colour is similar to that of purpurescens, namely a dark 

 blue-grey. My specimens, however, wdiich have now been two 

 years in spirit, show lighter patches dotted over the body, but not 

 sufficiently large to alter the general colour to the naked eye. In 

 other respects they agree with Tullberg's description. 



Xentlla maeitima, Tullb. (PI. I. figs. 6-10.) 

 The genus Xenylla contains at present four species, none of 

 which, as far as I am aware, have yet been found in England. 

 Tullberg distinguishes it from AcJioruies as follows : — " Ocelli 

 10 ; 5 in utroque latere capitis. Organa postantennalia desunt. 

 Turcula parva, non ad tubum ventralem pertinens spinae anales 

 2 " $. The real distinctions of Xenylla are as follows : — The 

 sprmg, which is short (extremely so in X. hrevicaiida and X. 

 niiida), is of a peculiar construction. The manubrium is almost 

 triangular in shape ; and the dentes taper so suddenly into the 



*■ Sveriges Pod lu'i tier, 1872. 



t Skau. Podur. af Underfaiu. LipiiriutB, 1869. 



\ Sveriges Podurider, 1872, p. 52. 



