Ao. 2323. LARVAE OP THE CLERIDAE—BOVING AND CHAMPLAIN. 577 



digitiform with ampullae or vermiform, in the poorly colored or 

 whitish genera which live permanently hidden in the galleries of 

 their prey. 



The Head is directed forward and protruded in free living genera ; 

 somewhat invaginate in the hidden forms. The dorsal surface of 

 the head is flattened, the sides subparallel, and the ventral surface 

 moderately convex in most of the free living genera, as Necrohia^ 

 Enoclerus^ and Cymatodera; the sides of the head are curved, pos- 

 teriorly diverging, and the head capsule as a whole subconical in the 

 genera CJiariessa^ Phyllohaeniis^ and allies; the dorsal surface is 

 short and flat, the sides posteriorly diverging, and the ventral surface 

 large and very convex in Priocera; dorsal surface convex, sides par- 

 allel, and ventral surface flat in Thaneroclerus. 



The Frons (/) is in most genera simple triangular, limited by 

 straight or slightly curved frontal sutures, which posteriorly form 

 an acute angle and reach the occipital foramen; in Hydnocera a 

 quadrangular frons occurs, posteriorly limited by a transverse line 

 and laterally by straight frontal sutures (/s), which reach the occi- 

 pital foramen separately ; in Fnocera the frons is anteriorly broadly 

 subquadrangular, posteriorly contracted into a narrow, stalk-like pro- 

 jection, which reaches the occipital foramen ; finally, in Thaneroclerus 

 the frontal sutures do not reach the occipital foramen, but meet in 

 front of it. The dorsal surface of the frons is usually without con- 

 spicuous sculpture; in Priocera castariea and Monophylla terminata^ 

 however, it bears a prominent median unpaired elevation. Epistoma 

 {ep), the anterior marginal thickening of frons between the upper 

 articulations of the mandibles,^ is always chitinized, even in forms in 

 which the head is otherwise but slightly chitinized. Anguli fron- 

 tales {af) are present but not large. Medianly and internally a 

 longitudinal endocarina is present and well chitinized in all forms, 

 and often posteriorly widened like an arrowhead. 



The Epicranium {ecr) is dorsally completely separated by the frons 

 into two epicranial halves, except in Thaneroclerus^ where the halves 

 meet posteriorly in the middle line and form an epicranial suture; 

 ventrally the epicranial halves are continued behind the attachments 

 of the tentorial arms and are in all Clerids separated by an elongate 

 rectangular gula. The shape of the anterior or maxillary margin 

 {mh) of hypostoma^ is an important aid in the separation of the 

 groups. It is straight in several genera, as Enoclerus and Than^ro- 



1 According to Schiodte's terminology " epistoma " means tlie entire frons. 



2 Hypostoma is a structure, often of triangular form, along the ventral border of 

 the epicranium. Its anterior or maxillary margin is here understood as the inner margin 

 of hypostoma between the ventral mandibular articulation and the point of intersection 

 between hypostoma and anterior margin of gula ; in the Clerid larva this point of inter- 

 section is indicated by the posterior tip of cardo. 



1.44382— 20— Pi-oc.N.M.vol.ST^ 37 



