514 Scientific Proceedings, Royal Dublin Society. 



with two series of short, straight projections, also from the ventral surface of 

 the margin. Dorsally there is a transverse row of four long bristles, one 

 from each of the lateral angles being much longer than the median pair. 

 Between the latter there are two round and comparatively large punctures. 



The epipharynx (PI. XVIII, fig. 36) is closely attached to the ventral 

 surface of the labrum, and often difficult to define. It would appear to be a 

 membranous structure, having a series of four short, blunt projections at each 

 side of a somewhat triangular concave area. 



The mandible (PI. XVIII, figs. 29 and 30) is strong, firmly chitinised, dark 

 brown or black, prominently situated ventral to the labrum. The base is 

 roughly triangular in section, and the apex is divided into five strong blunt 

 teeth. From the ventral posterior angle a prominent condyle arises, which 

 articulates with the head capsule by means of an acetabulum formed in the 

 ventral anterior angle of the pleurostome. Dorsal to the condyle is the 

 insertion of the abductor muscle, whilst the much stronger adductor is 

 attached to the inner surface of the dorsal posterior angle. 



The mandible is strongly arched, and carries on the outside towards the 

 posterior margin two small bristles. The molar region is provided with two 

 sharp, stout spines, which project inwards towards the buccal cavity. The 

 anterior spine is larger and distinctly curved. 



The maxilla (PI. XVIII, figs. 31, 33) is pi'ominent by reason of the fleshy 

 stipes and projecting palps. It consists of galea (gal.) and lacinia {lac.) 

 imperfectly divided ; palp (mp.), supported by a large palpifer ip/m.) ; large 

 stipes (st.) ; and small basal cardo (c). The cardo is soft and little chitinised, 

 roughly rectangular, and has a process for articulation with the head at the 

 outside basal angle. It bears a single minute bristle towards the lateral 

 margin and posterior to the cardo-stipes joint. The stipes is strengthened 

 by a pronounced band of chitih, which extends anteriorly to encircle the 

 lacinial region on the inside. It carries one large and one small bristle, 

 between which is a single puncture. The galea is rounded and strengthened 

 by a chitinous band, which encircles the apex. The latter carries a number 

 of short, blunt spines, and one larger, two-segmented spine. 



On the ventral surface of the galea and slightly below the apex three 

 minute bristles occur, the innermost being longest, and placed on or near the 

 lacinial region. The lacinia cannot be separated from the galea. It consists 

 of a narrow band of tissue, from which there arise on the ventral face and 

 near the apex five long, slender bristles. These project inwai'ds, and normally 

 are in close contact with the hypopharynx. The palpifer is a stout structure, 

 strengthened by an enveloping band of chitin. It carries two small bi'istles 

 on the ventral surface, and has one round puncture just dorsal to the lateral 



