OF WASHINGTON. 345 



families of adephagous coleoptera. The introduction of the Am- 

 phizoidas between the Carabidas and the Pelobiidae requires but 

 slight alterations in the scheme proposed by him. 



Thus extended Schiodte's table may be given briefly as follows : 



PRINCIPAL TYPES OF LARVAE WITH EXSERTED, MOBILE TARSI, 

 BEARING CLAWS, ETC. 



I. MANDIBLES CLOSED (non-suctorial). 



a. Mandibles with a retinaculum (strongly toothed). 

 Spiracles open ; eight pairs on the abdomen. 

 Branchiae none. 



Ninth abdominal segment exserted ; anal segment exserted, motatory. 

 .Abdomen ambulatory. Legs ambulatory. 



i. Cicindflideg. 



External maxillary lobe arising from the palpigerous piece of the 

 Stipes, immovable. Maxillary stipes oblique. Maxillary grooves 

 impressed upon the gense. No cerci. Ocelli in fours. 



2. Carabidce. 



External maxillary lobe arising from the stipes, mobile. Maxillary 

 stipes porrect. Maxillary grooves none. Cerci present. Ocelli in 

 sixes. 



b. Mandibles with rudimentary retinaculum (denticulate). 



Spiracles in part closed ; eight pairs on the abdomen, the terminal 



pair alone open. 

 Branchiae none. 



Ninth abdominal segment concealed. Anal segment concealed. 

 Abdomen ambulatory. Legs ambulatory. 



3. Amphizoidcs. 



Eighth abdominal segment terminal, hardly prolonged, ending 

 in stigmata. Cerci short, spine-like, assisting in progression. 

 Maxillae lobed. 



c. Mandibles without retinaculum. 



Spiracles minute, seven pairs on the abdomen. 



Fasciculate, sanguiferous branchiae pendant from the thoracic seg 

 ments and the first three abdominal segments. 

 Ninth abdominal segment concealed. Anal segment concealed. 

 Abdomen natatory. Legs natatory. 



4. Pe lob tides. 



Eighth abdominal segment terminal, prolonged in a motatory 

 style. Cerci very long, natatory. Maxillae without lobes. 



