HYLES EUPHORBI/E. 219 



larva is then black to the lateral line, broken, however, by a series ot 

 yellow or green triangles of smaller or larger size, with one side 

 vertical against the base of the segment, another side at right angles, 

 running horizontally to the forward apex, which is just behind the 

 enlarged subdivision consisting of the first 3 subsegments, the third 

 side slopes obliquely backwards at an angle of about 45 . On 

 the thoracic and on the ist and 2nd abdominal segments the front apex 

 is cut off, giving this yellow or green area an irregular shape. 

 Situated on the enlarged ist subdivision of the segments is a subdorsal 

 series of brilliantly white rounded or oval spots ; in some larvae 

 there is a second row of much smaller spots beneath and rather 

 anterior to the spiracles, in other larvae this is quite absent. The 

 secondary body-hairs (analogous to the shagreen-hairs of other 

 species) are minute, very short, black bristles with their bases 

 not raised as mammillae, but, where they occur on a black 

 skin area, other than on the ist enlarged subsegment or in near 

 proximity to the subdorsal white spots, they are surrounded by 

 larger or smaller white specks. It is also curious to observe that, 

 where the black encroaches on the yellow or green (paler) areas, 

 it always does so at first as streaks and dots, at mid-distance 

 between the hair-bases, as though there was some antagonism 

 between the black pigment and the hair-base ; it is this feature that 

 produces the tessellated appearance so characteristic of the Eumorphid 

 (Theretra porcellus and Eumorpha elpenor) larvae, and no doubt it is 

 an analogous trend that, in Smerinthus and Sphinx, has produced 

 mammillae and pale or brighter coloured areas at the base of the 

 secondary hairs. Whether the primitive Sphingid larva had tessellations 

 or pigmented mammillae is doubtful, more probably the pigmented 

 specks of the Phryxid and Sesiid larvae represent the primary form. In 

 any case, we may consider that the secondary (shagreen, mam- 

 millary or pigmented) hairs are a phylogenetically old and important 

 character of the Sphingid larva. The spiracles are white, and beneath 

 them is a broad subspiracular stripe, yellow where it is raised and 

 flange-like near the spiracle, but green at the anterior and posterior 

 portions of the segments, whilst beneath is a band of black, speckled 

 with white. The venter and prolegs are green, but the side plates 

 of the prolegs are black. In some larvae, and in the 4th skin of most, 

 the black area is much increased, the black encroaching up the 

 segmental incisions, cutting up the ventral area into yellowish or 

 greenish spots surrounded with black, thus giving the pattern so often 

 found in twig-resting larvae of various families or superfamilies. Fourth 

 instar : The only change in larvae that have assumed the 4th skin, is 

 for the black and white to be increased at the expense of the yellow, the 

 green having merged into yellow. The horn is thicker and rougher. 

 The yellow on the head has deepened into vivid orange, and the medio- 

 dorsal stripe is also orange where it crosses the scutellum. [Bacot. 

 Larvae received from Dr. Chapman, early July, 1902.] Fifth (Adult) 

 instar : Very brilliantly and crudely coloured (strongly suggesting 

 warning coloration). In the black ground-colour, and the large yellow 

 shagreen-spots (and the more or less absence of these on the enlarged 

 ist subsegment), the larva bears a marked resemblance to that of 

 Celerio gallii. Head, anal plates and prolegs red ; a subdorsal series ot 

 large pale yellow spots from prothorax to the 8th abdominal, situated 



