LAEVAL FORMS OF COLEOPTERA 



4. Two or three pairs of hooks present on tergum of fifth abdomi- 



nal segment Cincindelidae"^^ (pi. 4 A-E) 



No hooks on fifth abdominal tergum 5 



5. Terminal setae of tarsus much shorter than claws ; retinaculum 



single or absent ;...;.... Carahidae^^ (pi. 4 F-I) 



Terminal setae of tarsus much longer than claws ; retinaculum 

 bicuspidate Omophronidae (pi. 5 A-E) 



6. Thoracic and abdominal spiracles present, biforous, and all lat- 



eral ; branchial prolongations absent ; ninth and tenth ab- 

 dominal segments separate ; tenth abdominal segment long, 



bifurcate, and attenuate Haliplidae-Haliplinae (pi. 5 



E-H) 

 Spiracles all absent ; branchial prolongations present ; ninth 

 and tenth abdominal segments fused into a bifurcate, ter- 

 minal segment H aUplida e-P eltod yt inae 



7. Head nutant ; mandible falcate and simple ; eighth abdominal 



spiracle absent. (Gills present below anterior part of body.) 



Hijgrohiidae (Hygrohia) (pi. 

 5 I, J, M) 

 Head porrect ; mandible not simple ; eighth abdominal spiracle 

 terminal. (Gills rarely present) 8 



8. Mandible with distinct retinaculum, inner margin neither sul- 



cate nor tubular ; legs f ossorial 



Noferidae (Notenis, Hydro- 



conthus, and Canthydrus 



(pi. 5 K, L, N-P) 



Mandible without distinct retinaculum, inner margin either 



sulcate or tubular; legs ambulatory or natatory 9 



9. Prothoracic presternum large and subquaclrate ; gula-* present, 



subquadrate or triangular ; gular suture double or anteriorly 



bifurcate Bytiscidae'-'' (pi. 6 A-H) 



Prothoracic presternum transverse, narrow, and band-shaped ; 

 gula absent ; gular suture median and simple. 



Ampkizoidae (pi. 7 A-H) 



B.I. CICINDELIDAE 



Key to Main Types of Larvae 

 1. Each of the paired protuberances on fifth abdominal segment 



with two hooks 2 



22b j^gy ^Q ^i^p main types of cicindelid larvae on pages 17-18. 

 ^^ Key to subfamilies of Carabidae on pages 18-23. 

 -* The plate or area which appears as the gula may be a mor- 

 phologically different structure, namely, a pair of medianly fused 

 pieces separated from the gular margin of the epicranium. How- 

 ever, for practical purposes, it is referred to as the gula. 

 -■' Key to subfamilies of Dytiscidae on pages 23-24. 



17 



