624 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 51. 



the mandible, conical with a big basal membrane (bm, fig. 8) ; first 

 joint wide but rather short (/, fig. 8) ; second joint (II, fig. 8) as long 

 as the first but only half as wide; from the membraneous distal end 

 of the second joint is emitted on the outerside a small transversely 

 divided third joint (///, fig. 8) and on the innerside a thin-walled, 

 soft sensory filament (fil, fig. 8) , which is a Uttle longer and more 

 slender than the third joint. 



The mandible (fig. 6) is falciform with acute apex and with a large 

 flattened base, which is developed into a convex molar shaped por- 

 tion (mo) above the flexor muscle (Jl) , and which is also flattened out 

 above the extensor muscle (ex); between the molar part and the apical 

 part (apx) is inserted a thin, broad, perlucid retinaculum (rim); the 

 basal portion bears externally one large scrobicular seta. The maxilla 

 (fig. 10) is connected with hypostoma (h) by a large, oblong articu- 

 lating membrane (cm, fig. 10) from the exterior margins of the cardo; 

 the posterior half of this membrane contains a flat chitinous plate, 

 in outline resembling a lobster claw (lo, fig. 10), but the plate is nor- 

 mally concealed, because that part of the membrane, as a rule, is in- 

 vaginated below the cardo; cardo (ca) is rather large, well chitinized 

 and dark separated from stipes by a fme suture; the ventral surface 

 of the stipes is of the same size and character as cardo, but while cardo 

 only consists of a ventral shell-shaped plate, stipes is a real tube- 

 shaped joint, though its dorsal side, facing the mouth cavity, is chit- 

 inized only at its distal end (std. I, fig. 8), while the rest is soft-skinned 

 and forms a part of the buccal membrane (std. II, fig. 7) ; the rest of 

 the mouth cavity is formed by 'the imderside of the labrum, the epi- 

 pharynx (eph, fig. 4) , the dorsal side of the rather mdistinct ligula (li, 

 fig. 9, 10), and the hypopharynx (hy, fig. 7), all of which are soft and 

 fleshy; the distal end of stipes is closed by a membrane, (stm, fig. 10), 

 which bears a big fleshy lacinia (la, fig. 10) and a short palpiger (pig, 

 fig. 10) ; lacinia has ventrally a slightly chitinized brownish surface, 

 which is very distinctly articulated with the rod-like, strongly chit- 

 inized interior margin of stipes (str, fig. 10); the anterior and dorsal 

 part of the lacinia is soft skmned (la, figs. 9, 10), provided with a num- 

 ber of short sensory peg-hke projections, with a few setae and with a 

 two-jointed appendix, the rudimentary galea (g, figs. 8, 10);^ palpiger 

 (pig, fig. 10) is stiffened by a semicircular chitinization (pgc); it carries 

 a three-jointed conical palpus, which is of nearly the same size and 

 shape as the antenna, with the corresponding joints ahnost equal in 

 length and width; the number and location of the setae are indicated 

 in figm-e 10; apical joint with sensory papillae (se). Submentmn 

 (sm), mentum (m), and stipes labii (l) are fleshy and are fused to- 



» Compare (o) A. G. Boving, Natiaral History of the Larvae of Donaciinae, p. 12, (6) G. Dimmock, 

 Algunas Coccinellidae de leuba, p. 301, in translation from the Spanish text: "I am inclined to believe 

 that this appendix . . . will prove to be a rudimentary lobe (see plate 51, fig. 17)." 



