AETOTROGUS. 61 



The specific name Lillj.eborgii having been used by 

 M. Boeck (prior to the publication of Thorell's work) 

 to designate an Asterocheres, which genus is, as I 

 think, identical with Artotrogus, I propose in this case 

 to substitute the word Boeckii for the unavoidably 

 disused Lilljeborgii. 



Possibly -the organs here called mandibles might 

 more properly be looked upon as palps only, in which 

 case the mandible proper is altogether absent. These 

 organs, whatever they are, are placed quite outside of 

 the base of the siphon, as is plainly shown in fig. 6, 

 and, except in A. magniceps, I have not found any 

 trace of a mandible included within the siphon itself. 

 Further research may show that the species here 

 asigned to Artotrogus include two distinct types of 

 structure as to the mouth organs, but I have not been 

 able to satisfy myself on this point, owing to lack of 

 specimens for dissection. 



2. Aetoteogus magniceps, nov. sp. PL XCIII, figs. 



Artotrogus orbicularis, Brady and Robertson. Brit. Assoc. 

 Report, p. 197 (1875). (Not Arto- 

 trogus orbicularis, Boeck.) 



First segment (fig. 1) equal in length to more than 

 half of the whole body, width equal to two thirds the 

 length of the body ; second, third, and fourth segments 

 narrow, and produced laterally into acutely angular 

 wing-like processes, which are directed backwards ; all 



