tieio Uciiaa of Aplcroi/s Hcxapod Insects. 'i33 



lalo insUucto, scgmciitis sex pioxitiiis subtiis ad apicein 



iitriiique seta brcvi tenui pilosa instructis, segiiicntO([iic anali 



setis duabus valdc elongatis setosis iminito. 



Were it not for the multiarticulate antennte and the subab- 



iloiiiinal appendages this insect would be to all intents the larva 



of a SlaphijUnus, and hence I propose for it the name of Cavipodea 



StaplujUnus, founded on this striking resemblance. 



Its colour is of a creamy white, and it is exceedingly active in 

 its motions, running with great agility. 



Several of the characters which I have described above will be 

 sufficient to separate this insect from the larvcc of all Coleopterous, 

 Lcpidopterous, Dipterous, Hymenopterous, Strepsiptcrous, Or- 

 thopterous, and Hemipterous insects. There is indeed consider- 

 able resemblance between it and the larvae of the Forjiculidce, but 

 these are not only well known but also disagree with the present 

 in the structure of the anal appendages and in the want of the 

 subabdominal ones. There only remains therefore to compare it 

 with tlie larvai of Ncuroplcra, some of vvliich have multiarticulate 

 antennoe and anal as well as subabdominal appendages, but wherever 

 this is the case these appendages are instruments of respiration 

 serving to separate the oxygen from the water in which such 

 larvae reside : such is the case with the l^phcmerideous, Phryga- 

 nideous, and Sialideous larvae. The larva of Ascalaphus, it is 

 true, is furnished with lateral abdominal filaments ; but these are 

 only prolonged processes of the common integument of the body. 

 I am compelled therefore to reject the idea that the insect is the 

 larva of any hexapod metamorphotic insect, and am thence com- 

 pelled to refer it to the classes o'l Anmdosa, whicli do not undergo 

 transformations. The Crustacea and Arachnida, from the number 

 of their feet and the general structure of their bodies, are at once 

 distinguished from this insect ; and the Myr'uipoda have already 

 been rejected, so that there only remains the orders Anoplnra and 

 Thysanura into which it can possibly enter. These are hexapod 

 groups, the former being distinguished by the non -possession of 

 elongated anal seta; and by the structure of the legs, which are 

 short and strong and well adapted to a parasitic life. Some of 

 the Tlvjsanura, on the other hand, are furnished with elongated 

 anal seta, long multiarticulate antenna?, and long cursorial feet. 

 And M. Guerin has recently discovered in Maclnjlis poli/poda a 

 series of small subabdominal appendages similar to those in my 

 insect, and which he has illustrated in his Iconographie du Regne 

 Animal. The Podurcc and allied genera, on the other hand, are 

 cylindrical, with an inliexed fork at the end of the body, whilst 



