( Ixii ) 

 nioutli-parts oocur goncrally foj^etlior, ami are accompanied liy the appearance 

 of roughness in the scaling of the head and often b)' the appearance of scales 

 on the pilifer and tongne in jilace of bristles and hairs. The roughness of the 

 scaling is here a sign of weakness of the species, suggesting an analogy with 

 the shaggincss of weakly imliriiliiidx of mammals. 



T.ittle has been published bearing on the comparative mor])hology of the 

 trunk of the thorax of Lejiidojitera, authors having confined themselves generally 

 to a conij)arison of the thorax of the Lipuloptera Jiiynta with that of the 

 Frenata One of us has given an account of the mesosternite of the Rliopa- 

 locera,* and tried to unravel the homology of the various plates composing 

 the sternal part of the mesothorax. Onr researches on the thorax of the 

 Ili'tcrocera are not yet ripe for publication. The sterna of the various 

 Hetorccerons families are more equally developed than in the families of 

 Butterflies : such s]iecialisations as we have found there do not occur here. 

 But there are also in the lleterocera thoracic characters distinctive of genera, 

 tribes, and families. The most variable part of the thorax within a Heterocerons 

 family is generally the mefauotum. We shall restrict onr descrijition to the 

 thorax of the Sphhujiilm'. 



The denuded jirothorax does not apparently offer characters of taxonomic 

 valne in this family. The mesouotum (PI. LXII. f (i, dorsal view; PI. LXIII. 

 f. 1, lateral view), comjjosed of the praescutum, scutum, and postscutum 

 (= sentellnni), is very large, as in most Fn'mita, occupying bv far the larger 

 jiart of the uotal region, tlie pro- and metanotnm 1 eing quite small as compared 

 with the mesunotnm. The pi'aescntnm {jjsc) is distinctly triangular in dorsal 

 view, penetrating between the halves of the scutum, or it is transverse. It is 

 vertical in lateral as])ect. The scutum {jtisc) is widest behind and little longer 

 than broad : the mesial sutnre vanishes in front or is here vestigial. The 

 postscntum (nisrlj varies obviously in size and shape (PI. I^XII. f 0. 8), the 

 anterior and jiosterior angles being more acute in Macrof/h.'isi/m, >St'sifi, and some 

 allies tlian hi most other Spliii/qiiliir. 



The praescutum of the metanotnm is not visible in the figures. The scutum 

 {mt.tr) is divided like that of tlie mesouotum, but the two halves are widely 

 separate, the jiostscutnm of the mesonotnm pnijecting between them. The 

 postscutum {mtscl) is always narrow. In Senia and allies (PI. LXII. f (i) it is 

 overlajijied by the niesothoracical postscutum, which reaches to the first abdominal 

 tcrgite, while it is free in the other SphiiiyUlue (PI. LXII. f 8 ; PI. LXIII. f. 1). 

 The ventral parts of the meso- and metathorax are never so different in 

 size in any Frenata as are the nota, though also here the mesothorax is the 

 larger of the two. PI. LXII. f T represents the mesosternite in a frontal 

 aspect, the dorsal and ventral mesothoracical cndoskeleton {endosc) being visible 

 in the cavity of the thorax. The mesial i)lates of the sternite, the sternum (st), 

 and peristernum (pex/) are not completely separated from one another ; the 

 sternum is elongate-triangular; there is generally a small membranaceous area 



• I'crli. r. Intmi, /ool . O'lli/rcsi p. SKI. t. 1. 2. 3 (1902). 



