Nov. 5. 1921 Biology of Embaphion muricatum 327 



10 times longer than wide; dorsally verj'^ convex, ventrally flattened; pygidium 

 movable in the directions up and down, subconical, obtusely pointed. Head, ven- 

 tral sides of the thoracic segments and of the first abdominal segment, legs, and 

 pygidium (PI. 32, C) clothed with rigid or soft setae; rest of body glabrous with very 

 few and small ventral hairs. 



Cranium (PI. 31, B) rounded, nutant, exserted, one-third broader than long (from 

 epistomal margin (epi) to foramen occipitale), broadest medianly, dorsally somewhat 

 convex. Anterior frontal angle (fa) low and rounded. Frons (/) three-fourths the 

 length of cranium, about as long as wide with extreme width anteriorly, side margin 

 convex. Epicranial halves (epc) meeting dorsally; epicranial sutiue one-fourth the 

 length of cranium; ventrally (PI. 31, E) the halves are separated by gula (gu); dor- 

 sally with a few, laterally and ventrally with many hairs. Gula and submentum 

 (sm) both distinct, coriaceous. Gula almost square, with tentorial pits (ip) at the 

 middle of the side margins. Submentum trapezoidal, broadest posteriorly; side 

 margins slightly concave and adjacent to maxillary articulating area. Clypeus 

 (cl, PI. 31, B) trapezoidal, widest behind, length to extreme width as one to four, 

 medianly with slight transverse deepening, set on each side with one minute seta 

 near the middle line and two well-developed setae near the lateral margin. Labrum 

 well-developed, movable, transversely rectangular, length to width as one to three, 

 anterior margin almost straight, anterior comers rounded; disk on each half with a 

 median transverse series of five large setae, and an anterior series of three long, thin, 

 and straight setae; right behind those but on the ventral side of labrum another series 

 of four shorter, stronger, and ciurved setae. Epipharynx (eph, PI. 31, A) forming the 

 buccal surface of labrum, soft-skinned with posterior transverse, broad, sinuous, chitin- 

 ous band, that carries one pair of stublike sharp teeth; on the soft-skinned part 

 anteriorly to these teeth a pair of tiny hooks; near anterior margin scattered minute 

 setae and ring-shaped punctitfes. Just behind antenna two ophthalmic spots, both 

 transverse, slightly posteriorly convex, the anterior a little more external and about 

 three times longer than the posterior; immediately in front of the anterior are numer- 

 ous setae; the ophthalmic spots are likely to disappear in full-grown larvae. Antenna 

 (PI. 31, B) closely behind the mandible, attached in articular cavity with distinct 

 border; basal antennal membrane well developed; basal article cylindrical, about as 

 long as epicranial suture, second article as long as basal article, more clavate, apical 

 article very small, conical, papilliform, carrying one seta; no supplementary appendix 

 besides the apical article. Mandibles (Pi. 31, F) of right and left side differing in 

 shape; both apically bifid (a^, a^); both with one tooth (/) between apex and molar 

 part (m); tooth of right mandible, however, prominent and placed near apex, that of 

 left mandible less developed and placed closer to molar part; molar part of right mandi- 

 ble with bituberculate crown, that of left mandible with hollow crown; ventrally (PI. 

 31, D) with cutting part deeply excavated; exterior stirface ("the back of the mandi- 

 ble") distally with a slightly carinate margin (PI. 31, F, c), proximally with a soft- 

 skinned, whitish swelling (s) from an excavation (e) opposite the molar part; three 

 to four strong setae from the anterior portion of the swelling, two from the posterior, 

 several small, soft setae near dorsal mandibular articulation. Maxilla dorsally com- 

 pletely covered by mandible; palp (PI. 31, E) siu-mouiiting mala (ma) (maxillary 

 lobe) with one-third of its own length; palpiger (pag) small, ring-shaped; basal article 

 about as wide as long, second article cylindrical, somewhat narrower and more than 

 twice as long as basal article, apical article two-thirds as long and half as thick as the 

 second, conical, with soft tip; each article with one or two thin setae; mala (ma) on 

 buccal stuface (PI. 32, F) with two series of well-developed, somewhat curved setae; 

 base of stipes (PI. 31, E, bs) (that is, region where stipes and cardo meet) rather short; 

 proximal half of inner margin of stipes (is ,) connected with exterior half of maxillary 

 articulating area (ar^), distal half (js- 2) right behind mala, free; ventral stipital 

 surface with several strong setae; other setae on the exterior surface; cardo as long as 



