64 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.63. 



laterad of the median hooks. Legs without distinct, movable tarsal 

 claws, the distal end of the tarsi produced into two blunt, pointed 

 projections serving as claws. 



DESCRIPTION OF SPECIES. 

 CTENOSTOMA (?) sp«cies. 



Figs. 157, 1S2, 183, and 1S4. 



ScHWARz, E. A., not reared, larva in the collection of the U. S. National 

 Museum. 



Color. — Head and pronotum chestnut brov.n, with the region 

 around the ocelli, the anterior margin of the fronto-clypeo-labral 

 sclerite, and the anterior margin of the pronotum almost black ; setae 

 transparent. 



Head. — Setae on dorsal aspect fine and inconspicuous; diameter 

 of ocellus 2 distinctly greater than the distance between ocelli 1 and 

 2; fronto-clypeo-labral area longer than wide, ridge on the caudal 

 part of frons sinuate, prominent, and bearing a single prominent 

 setae; antenna with the i^roximal, second, and third segments sub- 

 equal, the distal segment one-half to two-thirds the length of the 

 third, the proximal and second segments each with five or six setae, 

 the third Avith two setae, and the distal with one; maxilla with the 

 proximal segment of the galea bearing three setae on its mesal mar- 

 gin, maxillary palpus three-segmented, each segment slightly in- 

 creasing in length toward the distal; ligula with four fine setae ar- 

 I'anged in a transverse row at its ventro-distal end, proximal seg- 

 ment of labial palpus with two spinelike projections on its ventro- 

 distal margin and with two setae on each side of these spines, the 

 proximal segment Avith four setae and the distal segunent with one. 



Thorax. — Pronotum with the cephalo-lateral angles extending 

 almost as far cephalad as the mesal, chitinized portion, lateral mar- 

 gins carinate, an oblong-oval, slightly raised mound on each lateral 

 part ; setae short, stout, numerous, and inserted on small setal moimds 

 (fig. 157). 



Abdomen.' — Chitinized areas indistinct, setae fine and not numer- 

 ous (fig. 183) ; ninth abdominal sternum with the caudal margin 

 bearing two groups of four setae each and the tergum with two 

 short spines on the caudal margin; tenth abdominal segment with 

 four short, stout spines on its dorsal margin and with each lateral 

 sclerite produced caudad into a short, blunt, chitinized projection 

 (fig. 183) ; fifth abdominal segment with three pairs of hooks, the 

 inner hook Avith tAvo short, stout setae, the median hooks Avith three 

 line, inconsi:)icuous setae (fig. 184). 



Measurements. — Length of larvae, 17 mm., Avidth at the third 

 abdominal segment, 2.5 mm.; diameter of ocellus 2, 0.31 mm.; dis- 



