268 Dr. Malcolm Burr on Opisthomeres and Gonapophyses. 



us to define the species in this difficult group. Zacher 

 figures the gonapophyses of several species; I add those 

 of Ecliinosoma afrum. 



The existence of gonapophyses in the AUosfethinae has 

 apparently been hitherto overlooked, even by such acute 

 observers as Verhoefi and Zacher, so I was rather sur- 

 prised to come across them ; both pairs are in the form of 

 short, rounded lobes, of about equal size; unfortunately, 

 I had no fresh nor spirit-preserved material available for 

 study in this case, but was obliged to dissect very old dried 

 specimens, after treatment with potash ; owing to the dirt 

 accumulated from the decomposition and desiccation of 

 the contents of the abdomen, all the specimens were 

 obscured and discoloured, and I was not able to produce a 

 satisfactory mount for illustration. 



These curious organs have not yet been investigated 

 with anything approaching thoroughness, and it remains 

 to be ascertained whether they are of use to the possessor 

 from a functional, or to the entomologist from a taxo- 

 nomic, point of view. They certainly are a primitive fea- 

 ture ; they have not yet been recorded in the Eudermaptera, 

 nor in the Labiduridae, with the above-mentioned exception 

 of the Alios tethinae ; till they were found here, they were 

 considered to be characteristic of the Pygidicranidae, since 

 they occur in the Diplatyinae, Anataelinae, Pygidicraninae, 

 and the Echinosomatinae. Unfortunately for the sake of 

 symmetry, they seem to be absent in the Pyragrinae, 

 though they may yet be detected here when fresh speci- 

 mens are available. 



But the facts so far adduced place us at once in a 

 dilemma ; are we to place the Allostethinae in the Pygidi- 

 cranidae, in spite of its undoubted Labidurine affinities ? 

 They seem really to represent an intermediate group, 

 with highly characteristic features of their own, which 

 they do not share either with the Pygidicranidae, or with 

 the Labiduridae. 



