NO. II LARVAE OF THE ELATERID BEETLES GLEN 1 95 



should be recognized as a genus or merely as one or more "species 

 groups" under Athous is open to question. On the basis of larval 

 characters Hcinicrepidius is not more distinct from Athous than are 

 the "species groups" of Athous (enumerated in section IV) from one 

 another. The other half of Athous, as represented by the vittatus and 

 nififrons groups, is closely allied to Elathoiis and Lcpturoidcs. In 

 fact, Lepturoides is not more distinct from these groups of Athous 

 than these are from each other. Ehithoits, on the other hand, appears 

 to fill the gap between Limonius and Athous (pars) and probably 

 should be retained as a distinct genus. The rather fragmentary larval 

 record suggests, therefore, that Athous be revised into two genera, 

 as in sections III and IV and that Hemicrepidius might be included 

 with the one part and Lepturoides with the other, or these retained as 

 distinct genera as at present. Elathous should remain as a genus. 



The writer is fully in accord with Van Dyke (1932, p. 356), who 

 states that Elathous bicolor (LeConte) should not be included with 

 the genus Leptoschema Horn. On the basis of larval characters 

 Leptoschenia belongs in the subfamily Elaterinae. 



THE GENUS LIMONIUS 



Limonius is less complex than Ludius and Athous. This is shown 

 on page 191, the genus being confined to section III. However, the 

 larvae exhibit considerable polymorphism, mainly in characters of 

 the mandibles, nasale, and urogomphi. At present, it would appear 

 premature to erect genera on these characters. However, if any re- 

 vision of the genus were to be made on the basis of larval characters 

 the following subdivisions are suggested : 



Subdivision i : the aciiconigcr group ; these larvae are well characterized by the 

 mandibles, nasale, subnasale, and small outer urogomphal prongs. 



Subdivision 2: L. pilosus (Leske) and its allies; the single-pointed nasale, the 

 subnasale, and the mandibles isolate this larval type. 



Subdivision 3 : includes all remaining species of Limonius known in the larval 

 stage. This subdivision brings together rather diverse forms, but the chief 

 difference is that pcctoralis, acgcr, and conftisiis ( ?) all have very small 

 outer prongs whereas the members of the camis group have well-developed 

 outer prongs. However, this character does not appear to have high ordinal 

 value, especially since acger is obviously related to the canus group through 

 several other characters. 



THE GENERA HYPNOIDUS AND CRYPTOHYPNUS 



There has been a tendency in recent years for taxonomists to 

 suppress the genus Cryptohypnus and to place its species under 



