16 ILLINOIS BIOLOGICAL MONOGRAPHS [248 



in Epilachna (Fig. 16, mxpl) is much elongated, the proximal segment is 

 nearly twice as long as wide, the second segment more than twice as long 

 as wide, and the conical third segment nearly three times as long as wide. 

 In all of the other genera the maxillary palpus resembles that of C. bivul- 

 nerus and the distal segment of each bears a group of peg-like organs, 

 tactile setae. 



The galea (Fig. 18, ga) in C. bivulnerus is the broad triangular area dis- 

 tad of the palpifer. Its shape and structure is more or less constant 

 throughout the family, the most notable exception being found in Hyperas- 

 pis (Fig. 27, ga). In this genus the galea is rounded and appears to be 

 more or less sponge-like and bears a few setae. In Epilachna (Fig. 16, 

 ga) the distal margin of the galea is densely setaceous, while in all of the 

 other genera of the family it bears only a few setae. There is a peg-like 

 structure on the galea that bears a striking resemblance to the distagalea; 

 this is nothing more than a tactile seta and cannot be interpreted as a 

 distagalea. 



The mesal margins of the maxillae and the lateral margins of the labium 

 are connected in all of the genera by a distinct membrane, the labiacoria 

 (Fig. 18, lie). The lateral margins of the maxillae and the mandibles are 

 connected by a similar membrane, the maxacoria (Fig. 18, mxc). An 

 extension of the maxacoria connects the stipes and cardo of each side to a 

 postgena. 



The labium of coccinellid larvae differs considerably from that found 

 in the more primitive forms, as the larvae of Corydalis and the adults of 

 Periplaneta. Many of the parts seem to be lacking. The type of labium 

 found in the more generalized coleopterous larvae shows but little resem- 

 blance to the coccinellid labium. By a study of the labia of the primitive 

 forms named and of the more generalized Coleoptera, one is able to homol- 

 ogize the parts. 



The labium of C. bivulnerus is the more or less membraneous area 

 cephalad and ventrad of the gula and between the maxillae. It appears 

 to be made up of two parts, the submentum (Fig. 18, su) and the ligula 

 (Fig. 18, lig.). The mentum is indistinguishable or fused with the ligula. 

 The submentum (Fig. 18, su) is the large proximal portion. It is mem- 

 braneous, more or less rectangular, usually with four setae, two large ones 

 which decussate, and two smaller ones. In Anatis, Megilla, Coccinella, 

 and Hippodamia there may be many setae on the submentum, the number 

 varying from four in Hippodamia convergens to eighteen in Anatis. The 

 submentum is not clearly or distinctly separated from the ligula in C. 

 bivulnerus but there is a distinct division between the two in Epilachna 

 (Fig. 16), while in Hyperaspis (Fig. 27) the division between the ligula and 

 submentum is entirely obsolete. In all of the other genera studied the 

 condition of this division approximates that found in Chilocorus. The 



