270 BULLETIN 18 2, UNITED STATES NATIONAL MUSEUM 



Specimens examined. — I have seen only the unique type. 



Remarks. — This species is distinguished by its dense ground sculp- 

 ture and rather dense umbilicate punctures of head and pronotum 

 and strongly tuberculate sculpture of elytra. It belongs in the 

 subgenus Hyyomedon. I have no record of its habits. 



XXXVI. Genus MEDON StephenH 



Medon Stephens, 1832, p. 273. 



Oxymcdon Casey, 1905, p. 177. 



Subgenus Platymedon Casey, 1889a, p. 184. 



Paramedon Casey, 1905, p. 1G6. 

 Subgenus Medonodonia Casey, 1905, p. 176. 

 Subgenus Tetramedon Casey, 1905, p. 178. 



Genotype. — Medon ruddii Stephens (monobasic). Of Oxymedon, 



0. i^uhmm Casey (monobasic) ; of Medonodonta., M. alutacea Casey 

 (monobasic) ; of Paramedon^ P. arizonicum Casey (designated by 

 Blackwelder, 1939) ; of Platymedon., P. laticollis Casey (monobasic) ; 

 of Tetrainedon., T. rufipenne Casey (monobasic). 



Diagnosis. — Body elongate, moderately convex; punctures of head 

 umbilicate; antennae posteriorly flexible, not strongly geniculate, 

 basal segment not much elongate, first two not much larger than 

 rest; labrum without median denticle, with one or two pairs of 

 denticles near middle ; fourth segment of maxillary palpus very small, 

 subulate ; gular sutures not at all united, never very distant but most 

 approximate along middle or posteriorly; punctures of pronotum 

 more or less tuberculate; prosternum longitudinally carinate along 

 disk, prolonged posteriorly between coxae but not much dilated 

 beneath them; hypomera prolonged in a short lobe partially behind 

 the coxae ; anterior coxal cavities open behind, confluent ; front coxae 

 very large, exserted ; middle coxal cavities confluent ; posterior coxae 

 contiguous, "conical"; first and second abdominal sternites absent, 

 third carinate at base, seventh unmodified in both sexes, eighth ster- 

 nite not or feeblj' modified in male only. 



Remarks. — This name is used here in a restricted sense probably 

 about equivalent to the subgenus Medon of Bernhauer and Schubert. 

 It is not very abruptly distinguished from its close neighbors, but 

 in this status permits a more careful grouping of its species. 



I have seen 89 examples of this genus, belonging to seven new 

 species. 



KEY TO WEST INDIAN SPECIES OF MEDON 



1. Head with dense ground sculpture 2 



Head without dense ground sculpture 3 



2. Head distinctly longer than broad 7. cordatum 



Head distinctly broader than long 6. scliwarzi 



3. Midline of pronotum elevated, narrowly impunctate 4 



Midline of pronotum not elevated 5 



