( 53 ) 



flie apical spines often alone representing these rows, C. diiponchcl being tiie most 

 arlvanced species in tlie develoiiment of this tarsal armature ; in the ¥ the 

 spination more normal, the spines of row 3 not or less obviously directed laterad, 

 and rows ], 2, and 4 alwajs present, though the number of spines is generall}' 

 smaller than in row 3, segment 1 excepted. 



The transparent, sjiaces on the disc of the hind wing are the result of the 

 obliteration of the lower layer of scales and of the modification into hair-scales of 

 the scales of the upper layer ; this development is vestigial in cluentiiis and 

 beelzi'hitth, which do not possess the large transparent sjiaces ; a similar develop- 

 ment is observable on the forewing, where the scales in the jiroximal half or 

 two-thirds of cellules R' — M'' are half erect in several species and, esjiecially on 

 the under surface, reduced in size. 



Larva : clothed with fine hairs ; head narrowing above, subtriangnlar : lioni 

 grannlose, curving downward ; one or more white side-bands. — Food : Aiwi/ac'i>tie. 



Pupa: tongue-case free, either sjiirally recurved (duentiits), or not recurved 

 with the end resting against the breast, jirominently ringed ; metauotum with two 

 patches of rough tubercles, abdominal segments 2 to S, or 2 to 7 with a long, 

 transverse, basal patch of tlie same rough structure ; a short tuberculated ridge 

 behind the first stigma at the anterior edge of the mesonotum, cremaster 

 acuminated, ending in two points. 



Ilalj. Tropical and subtropical America, occasionally farther north as a straggler. 



Five species. 



The genus contains tlie largest Sphingids. Its species have the longest 

 tongue, measuring in large cluentius .about 25 mm. (Smith, in Trans. Amer. Eiif. 

 Soc. XV. p. 152 (1888) curiously states that the tongue slightly exceeds the tiji of 

 the abdomen in length). 



Key to the species : 



a. Hiudwing without transparent discal inter- 



spaces ....... 



Hind wing with transparent discal interspaces. 



b. Abdomen with five yellow spots 

 Abdomen with three yellow spots . 



c. Transparent spaces distally indented between 



the veins ....... 



Transparent spaces not indented between the 

 veins ....... 



'/. I'ostdiscal line of forewing crossing SC'' nearer 

 apex of wing than upjier angle of cell ; 

 forewing of ? with white apical j)atcli and 

 other white markings, c? more uniform in 

 colour, black streaks R'' — M- not very 

 prominent on account of the dark ground 



(•(dour of the wing 33. C. (hipoiii'ln'l. 



I'ostdiscal line crossing iS( ;•• midway between 

 apex of wing and upper angle of cell, or 

 nearer cell ; forewing similar in the sexes, 

 paler than in untacus, discal streaks 

 W — M''' jirominent : no (ibvimis white 

 markings, besides stigniii. . . . 35. C. liwifcr. 



