( 53 ) 



flip ajiical spines often alone represcMitini,' fliese rows, C. duponehcl lieing tJie inosf, 

 advanced species in tlie develo]iment, of this tarsal armature ; in the ? tlie 

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

 and rows 1, 2, and 4 always present, though the numhcr of s]iiiies is generally 

 smaller than in row 3, segment 1 excepted. 



The transparent s])acos on the disc of the hindwing are the result of the 

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

 tiie scales of the upper layer ; tiiis development is vestigial in chioititia and 

 bt'elzpbuth, which do not possess the large transjmrent spaces ; a similar develop- 

 ment is observable on the forewing, where the scales in the proximal lialf or 

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

 the under surface, reduced in size. 



Larva : clothed with tine hairs ; head narrowing above, sulitriangnlar : horn 

 granulose, curving downward ; one or more white side-bands. — Food : Aiioiirfccae. 



Pujia : tongue-case free, eitlier sjiirally recurved (duentius), or not recurved 

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

 patches of rough tubercles, abdominal segments 2 to 8, or 2 to 7 with a long, 

 transverse, basal patch of the same I'ough structure ; a short tubercnlated ridge 

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

 acuminated, ending in two points. 



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



Five species. 



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

 tongue, measuring in large duentius about 25 mm. (Smith, in Trans. Amer. Ent. 

 Soe. XV. p. 152 (1888) curiously stages that the tongue slightly exceeds the ti]) of 

 the abdomen in length). 



Key to the species : 



a. Hindwing without transparent discal inter- 



spaces b. 



Hindwing with transparent discal interspaces. . c. 



b. Abdomen with five yellow spots 

 Abdomen with tiiree yellow spots . 



c. Transparent spaces distally indented between 



the veins ....... 



Transparent spaces not indented between the 



veins ....... 



(I. Postdiscal line of forewing crossing SO'* nearer 



apex of wing tlian upper angle of cell ; 



forewing of ? with white apical patch and 



other white markings, d more uniform in 



colour, black streaks R^ — M- not very 



prominent on account of the dark ground 



colour of the wing . . . . .33. C. (hipoiwhel. 

 Postdiscal line crossing SC' midway between 



apex of wing and upper angle of cell, or 



nearer cell ; forewing similar in the sexes, 



paler than in antueus, discal streaks 



W — M- prominent : no obvious white 



markings, besides stigma .... 35. C. hicifcr. 



