NO. 2171, SYNOPSIS OF THE COCCINELLID LARVAE— BOVING. 629 



The following genera are represented in the United States National 

 Museum, several of them by more than one species:^ Hyperaspis, 

 Thalassa, Brachyacantha, Microweisea, Stethorus, Scymnus, CepJialo- 

 scymnus, Cryptolaemus, Novius (Vedalia), Lindorus, Khyzobius, Mi- 

 craspis, Anisosticta, Megilla, Hippodamia, Adalia, Coccinella, Har- 

 monia, Neda, Cycloneda, Anatis, SynonycJia, Thea, Psyllohora, Epi- 

 lachna, Lasia, Cynegetis, Curinus, Axion, Exochomus, Egius, Orcus, 

 Chilocorus. In the subsequent synopsis these genera are arranged 

 in nine groups, namely (1) Hyperaspini, (2) the genus Microweisea, 

 (3) Scymnini, (4) Noviini, (5) Rliyzobiini, (6) Coccinellini, (7) Psyl- 

 loborini, (8) Epilaclinini, and (9) CMlocorini. 



These nme groups are differentiated, as shown on plate 120, by the 

 following characters : ^ 



Primarily: 



(1) The location of the thoracic spiracles; these are situated either 

 in tergum or in the protopleurite. 



(2) The arrangement of the pleural areas of meso- and metathorax; 

 these are either similar to the corresponding, normally arranged 

 pleural areas of the abdomen, or differ from these in having the pro- 

 topleurite more or less fused with the adjacent part of tergum into a 

 triangular region, which extends downwards to the sterno-pleural 

 suture, and in having the pleural lohe fused with the posterior pleurites 

 into another triangular region, which extends upwards from the ster- 

 nopleural suture. 



(3) The presence or absence, distribution, or modification of proc- 

 esses, tubercles, plates, or spines on the thoracic and abdominal areas. 



Secondarily: 



(4) The different development and chitinization of the hypopha- 

 ryngeal bridge. 



(5) The shape of the apex and the retinaculum of the mandibles. 

 The relationship of the genera and groups is, as far as possible, 



indicated by the sequence withm the columns of plate 120. 



It is noteworthy that this systematic arrangement, based on struc- 

 tures of the larvae, corroborates the classification based on structures 

 of the adults, proposed by Col. Thomas L. Casey,^ deviating only in a 

 few points; thus the study of the larvae does not support a separation 

 between a tribe Hypodamiini and a tribe Coccinellini. The genus 

 Microweisea ( = T. L. Casey: the genus Smilia, Weise) forms, as 

 Weise and Casey have pointed out for the imagoes, an extremely 

 remarkable and isolated type which can not be included within the 



1 The large number of Danish forms is due to the gifts of Messrs. Kryger and Rosenberg, of Copenha- 

 gen. 



2 As muscle impressions corresponding to those described in Hyperaspis binotata are present in all Coc- 

 cinellid larvae, and as the areas defined by them consequently can be identified with the homologous 

 areas in Hyperaspis, all tubercles, sclerites, spines, or glands are referred to these special areas and named 

 after them. 



s A Revision of the American Coccinellidae, Journ. New York Entom. Soc, vol. G, 1898. 



