6 PKOCEEDINGS OF THE NATIONAL MUSEUM. vol. 66. 



5. Dorsal side of ligula not densely setose. Eulabium with posterior setae 

 branched. Marginal setae of epipharynx all branched. Intersegmental 



area present in front of praescutum Cosmopolites, p. 7. 



Dorsal side of ligula densely setose. Eulabium with simple setae. Margi- 

 nal setae of epipharynx not all branched. No intersegmental fold in front 



of praescutum 6 



G. Mala distally truncate Metamasius, p. 7. 



Mala distally rounded Calendra, p. 7. 



7. Mala distally truncate, proximally on dorsal side thick set with setae. 



Large forms about 35 mm. in length Rhynchophorus, p. 8. 



Mala distally rounded. Proximally on dorsal side with none or a few 

 setae 



8. Dorsal (or buccal) side of mala with eight branched setae. Eulabium with 



simple setae. Marginal setae of epipharynx mostly simple, only a few 



branched Scyphophorus, p. 8. 



Dorsal (or buccal) side of mala with more than eight branched setae. 

 Eulabium with, branched setae. Most of marginal setae of epipharynx 

 branched or tuft-like Yuccaborus, p. 8. 



Genus CACTOPHAGUS LeConte. 



Plate 1, figs. 1-7 ; plate 10, fig. 3. 



The larvae of this genus breed in Cactus plants and attain a length 

 of about 30 mm. Labrum with twelve simple, thickened, marginal 

 setae. Epipharynx somewhat setose and with two pairs of small 

 thickened setae between the epipharyngeal rods. Maxillary mala 

 oval at tip, with a row of seven simple and one branched setae on 

 dorsal surface and with three simple setae at tip. Ligula not setose. 

 Hypopharynx fleshy and laterally densely setose. Body with rows 

 of small spines. Abdominal terga above divided into three distinct 

 areas. Abdominal hypopleurum four-lobed. 



Genus RHODOBAENUS LeConte. 



Plate 2, figs. 1-7 ; plate 10, fig. 2. 



The larvae of this genus inhabit the stems of various weeds of the 

 Compositae. They are somewhat elongate and may attain a length 

 of about 16 mm. Labrum with twelve simple, thickened, marginal 

 setae. Epipharynx with two pairs of small thickened setae between 

 the epipharyngeal rods. Maxillary mala oval at tip, dorsal surface 

 with a longitudinal row of seven simple, stout setae, tip with three 

 simple setae. Ligula not setose. Hypopharynx fleshy and laterally 

 densely setose. Abdominal terga above divided into four distinct 

 areas. Abdominal hj^popleurum two or three lobed. 



Genus SITOPHILUS Schbnherr. 



Plate 3, figs. 1-7 ; plate 10, fig. 1. 



The larvae of this genus are seed inhabiting. The three species 

 found in North America are all small, none exceeding 3.5 mm. in 



