Mr. G. R. Waterhouse o7i Coleopterous Larva. 33 



This larva is found in the same situations as the perfect insect ; it 

 assumes the pupa state about the latter end of March ; the perfect 

 insect appears about the middle of May. 



Trox arenarius. Fab. 

 Larva and Pupa. Plate V. fig. 4. 



Head pitchy brown. Body of a subtransparent whitish colour, 

 the apical joints bent under, as in the larvae of the Geotrupidce . 



Length 4 — 4-^ lines. 



Head round and depressed, scarcely wider than the segments of 

 the abdomen ; the fore part is coarsely punctured. Labrum. 

 minute transverse, armed anteriorly with several very minute 

 tubercles. Mandibles short, unidentate internally. Maxillce 

 trilobed, the exterior lobe, or maxillary-palpi 3-jointed ; the in- 

 terior lobe armed with spines on the inner side. Antennae 

 3-jointed, the terminal joint minute. 



Body 12-jointed, and of equal thickness throughout ; all the seg- 

 ments (except the prothorax and apical) are subdivided into 

 three ; the thoracic joints each furnished with two legs. 



4 a. The natural size of the larva. 4 h. The larva magnified. 4 c. The 



mandible. 4 rf. The maxilla. 4 c. The antennae. 4/. The labrum. 



4^. The palpiger and labial palpi. 4 A. One of the central segments of the 



abdomen, side view. 4 i. The under side. Aj. Upper view of two segments. 

 4 A-. Foreleg. 4 I. The natural size of the pupa. 4 m. The pupa magnified. 



I have twice met with this larva in company with Trox arenarius, 

 and in such situations as rendered it highly probable that it was the 

 larva of that insect ; but lately I have had almost positive proofs, 

 my friend Mr. Pickering having found the larva, pupa*, and perfect 

 insect together : the first and last were in great profusion. Hence 

 without my friend's assistance I should not yet have been able to 

 describe this larva. I may add that I am also indebted to him for 

 information respecting several others. 



* It may be remarked that the pupae of Coleopterous insects so much resem- 

 ble the imago in the form of the head and thorax, that they cannot be easily mis- 

 taken when there is any peculiarity in the form and sculpture of that part, as is the 

 case in our present example. 



VOL. I. 



