50 BULI^ETIN 1107, V. S. DEPARTMENT OF AGRICULTURE. 



large, fleshy, hairy outer lobe (galea?) and a stylus-like process (lacinia?). 

 Palpiger maxillae large, conical, jointlike. Palpus maxillaris two-jointed. 

 Submentum large, separated from mentum by indistinct line. Mentum laterally 

 free or almost free. Stipites labii fused ; no distinct palpiger labii ; chitinous, 

 narrow, transverse line between stipites labii and mentum. Ligula (united 

 labial malse) present, ventrally and dorsally undivided. 



Thorax: Prothoras dorsally simple ; with oblique chitinous rod imbedded 

 laterally in tergum above and in front of first spiracle. Mesothorax and 

 metathorax dorsally duplicate. No hypopleural chitinization at base of 

 legs. Legs, when well developed, of medium size, four-jointed, hairy, with 

 tarsus claw-shaped and concavity facing forward, Avidely separated by inter- 

 mediate broad sternum. 



Abdomen: Typical (anterior and median) segments dorsally triplicate. 



Spiracles: Bilabiate; first spiracle above anterior margin of mesosternum, 

 somewhat larger than the following eight abdominal spiracles, which are all 

 of same size, all lateral, and all placed at lower margin of the terga. 



Habits: Wood-boring and wood-feeding. 



Relationship to other families: Close to the larvse representing the Anobiidae, 

 Ptinidae, Psoidae, and Lyctidae. Also connected with the Donaciidae as well 

 as with the Sagridae and Bruchidae by identity of several important morpho- 

 logical structures. The peculiar adaptation of the maxillary mala for sap- 

 sucking in the Donaciidae can, through the construction of this part in the 

 Plateumarini, be derived directly from the stylus-bearing mala in the Bos- 

 trichidae. This characteristic stylus formation occurs also in all the Dermes- 

 tidae. In several genera of this latter family is also found a thick interior 

 enforcement of the mandibular biting surface which corresponds to a similar 

 development in the mature bostrichid larva. 



SCOBICIA DECLIVIS LeCONTE. 



(Larvae of different stages in U. S. National Museum, Washing- 

 ton, D. C, labeled Hopk. U. S. 16178a4; from Los Gatos, Calif.; 

 collected and reared from eggs by R. T>. Hartman.) 



The larva of Scohicia declivis has six stages. In the first stage 

 several characters are exhibited deviating from those hitherto con- 

 sidered typical in bostrichid larvae. A full description will be given 

 of only the mature larva and this description will precede the 

 references to the other stages. 



GENERAL DESCEIPTION OF MATURE LARVA. 

 PI. I, Figs. 1-16 ; PI. II, Figs. 17-32. 



Length of larva: About 10 millimeters, width 2.50 millimeters. Straight line 

 between head and anus, when larva is curled. 6.85 millimeters. Length of 

 the combined thoracic segments in proportion to length of the combined ab- 

 dominal segments about as 1 : 2i (measured on imaginary lateral line through 

 the spii'acles). Largest vertical diameter of head in proportion to largest 

 vertical diameter of prothorax, about as 1 : 3. 



Head capsule (PI. II, Figs. 17-19) : Formed by fusion of frons and epicra- 

 nium ; elongate, subrectangular with rounded corners, twice as long as wide ; al- 

 most two-thirds retracted into prothorax ; whitish with heavy dark brown chitin- 

 ization anteriorly on each side. This chitinization is constituted by the lateral 

 part of epistoma (e, PI. II, Fig. 17), the entire pleurostoma {p, PI. II, Fig. 21), 

 the entire hypostoma between mandibular condyle and end of cardo (/;, PI. II, 

 Fig. 19), and by a triangular region extending posteriorly and laterally from 

 hypostoma as far back as the posterior margin of the tentorial bridge (PL 

 II, Fig. 19). It supports the clypeus and the mandible, is adjacent to the 

 exterior part of the maxilla, and surrounds the antenna, separating the antennal 

 basal skin from the mandibular connecting membrane (PI. II, Fig. 21). Ex- 

 posed parts of head capsule roughened by numerous granules and set with 

 light fine hair all over the surface ; a series of setas present, reaching from 

 antennal base obliquely upward and backward. 



Foramen in middle of ventral surface of head capsule: Elongate oval, almost 

 one-third as long as capsule ; posteriorly and laterally limited by sharply in- 

 folded margins of epicranium, anteriorly by tentorial bridge {th, PI. II, Fig. 19). 



