630 PROCEEDINGS OF THE NATIONAL MV8EUM. vol. 51. 



tribe Scymnini; the larvae also indicate that this genus constitutes a 

 separate tribe. Colonel Casey states that the two genera Psyllohora 

 and Thea are so closely related to each other, "that it might scarcely 

 be conducive to taxanomic convenience to maintain them distinct"; 

 the study of the larvae which are readily identified by the character- 

 istic shape of their mandibles (fig. 10, pi. 120), support this view. On 

 the other hand, the comparison between the larvae of the PsyUoborini 

 and the Epilachnini does not support Colonel Casey's opinions, when 

 he regards the PsyUoborini and the Epilaclmini so closely related, that 

 he considers the Epilachnini merely as slightly modified PsyUoborini 

 "by reason of perverted food habits and attendant environments." 

 While the larvae of the PsyUoborini are rather close to the CoccineUini, 

 the larvae of the Epilachnini differ considerably from both of them 

 in a great many characters. The Epilachnini are truly derived from 

 the CoccineUini, but are so adapted and changed that they form a very 

 distinct tribe. 



Group I (HYPERASPINI). 

 Plates 118-120. 



Of this group the following genera and species have been studied: 

 Eyperaspis lugubris Randall (N. Amer.), Hyperaspis binotata Say 

 (N. Amer.), Thalassa montezumae Mulsant (Arizona), Brachyacantha 

 ursina Fabricius (Washington, D. C), Brachyacantha, sp. (Texas). 



The body in dorsal view is ovate, with greatest width on the third 

 and fourth abdominal segments ; much flattened ventrally and very 

 convex dorsally. Prothorax oblong-oval, more than twice as broad 

 as long, the dorsal outhne of the other segments, both thoracic and 

 abdominal, is approximately rectangular, laterally rounded, com- 

 paratively broader and shorter than prothorax; the ninth abdominal 

 segment nearly semicircular, more than twice as broad as long, with 

 an unserrated margin. The folds and areas of mesothorax and meta 

 thorax are very similar to those of the abdominal segments, which 

 indicates the prunitive nature of the group ; the spiracles are all tergal 

 and the spiracle-bearing areas are developed nearly alike in the tho- 

 racic and the abdominal segments. The tergopleural suture is hori- 

 zontal and well defined throughout its whole length; the pleural 

 lobe is convex, cushion-like, ovate, and the protopleurite is not fused 

 with the adjacent part of tergum. Both thorax and abdomen have 

 small chitinizations, indicating the attachment of muscles, but have 

 no setiferous tubercles or spines. The hypopharyngeal bridge is 

 strongly chitinized with a cavity in each end, into which the molar- 

 shaped interior base of the mandible fits; the apex of the mandible is 

 single, and the retinaculmn is thin-walled with a single-pointed tip. 



