38 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Cremastochrysalis. Melanocera. and Cirina. It isr present in S Ci/rtagdin: aniu, hut absent in ? 

 C. herilla. In the Hemileucida' it is usually al)sent, though present in Coloradia. In Saturiiiida' 

 it i.s wanting, or very short, arising at the apex, and almost vestigial. 



It appears, then, that in the Sphingidre this vein, either atrophied or vestigial in the super- 

 family of Saturniides, has become revived, restored, and strengthened, and functi()n>»as one of 

 the important veins in the wing. Its presence is correlated with the narrowness of the whole 

 wing, the acuteness of the apex, and consequent greater strength of the fore wing, adapting 

 the moth for swift, powei-ful flight. It is to be observed that the bombycine character of but 

 three branches of the so called, or what was formerly the median vein (now, according to 

 Enderlein, medius 3, cubitus 1 and 2). are the same a.s in the superfamily Saturniides, while 

 the '"independent vein" (medius 2) is detached as in the saturniide, init this vein arises nearer 

 medius 3 than medius 1. in this respect differing from the position of this vein in Ceratocampinffi. 

 The anterior discal vein of the Smerinthinte also differs in its direction from that of the Cerato- 

 campina% being directed inward instead of outward, toward the origin of the hinder discal; this 

 produces a change in the shape of the discal cell, the outer side of the discal cell being parallel 

 with the outer edge of the wing instead of being at right angles to it, as in Ceratocampina>. (See 

 PI. XLITI.) 



The forking of the base of tiie axillary vein also occurs in the Ceratocampina?. 



The hind wings of the Sphingidaj differ fiom those of Saturniides in tkose characters which 

 seem to strengthen the wing; the bristle is present, so that both wings are locked together, and 

 an additional axillary (A,) is added, while the subcostal and radius is strengthened ])y a cross vein 

 arising from near the middle of the discal cell and anastomosing with the subcostal vein (II). 



Turning to the head with its appendages, we find that in the primitive Sinerinthinaj 

 there seem to be no positive diagnostic characters which separate them from the Cei'atocampina?. 

 The latter, like all the Saturniida?, have a large, long, broad, somewhat triangular or scutellate 

 clypeus, extending up and inclosing the aritennal foramina. As will be seen b\' reference to 

 PI. XXXVI, tigs. 6, 7, the shape and proportions of the front of the head of the two Smeiinthine 

 genera Marumba and Cressonia are nearly identical with those of the Ceratocampinse, as Eacles, 

 etc., except that the head is wider in front in the Sphinges. In the typical Sphinges with long 

 maxilkv the head is much larger, the front more convex, probably owing to the enlarged tongue 

 and its muscles. 



The antenna" of the typical Sphingidie are, as is well known, of a peculiar prismatic fusiform 

 shape, in the Macroglossin* with a terminal hook and no pectinations, but in Cressonia, which 

 has evidently retained the vestigial characters of its ceratocampid ancestors, with their broadly 

 pectinated antenna% the joints are doubly pectinate, or with two pairs to a joint, the pectinations 

 of the anterior pair being a little shorter than those of the basal pair. (PI. XXXVI, tigs. ,S, S<(.) 



The maxilla? of Cressonia, though scarcely "obsolete," as usually stated, being long enough 

 to form a roll when retracted, are but little longer than those of Eacles and Citheronia. It is a 

 very striking fact that while in the Smcrinthina', which appear to us to be pi'imitive rather than 

 degenerate forms, the maxilla? are so small as to be of little or at least very limited use. It 

 should be carefully' observed whether any of the Smerinthinw extend their maxilhe and probe the 

 corollas of flowers, like the typical Sphinges, or if they use the tongue to simply suck the sweets 

 of flowers while resting on their leaves or petals. It has been observed that Citheronia regal is 

 will be attracted by and sip the sugar laid as bait on trees. Its tongue is short and feeble, that of 

 Eacles a little longer, but in neither case extending as far as the end of the palpi. 



When we compare the small size and lack of development and use of the maxiihi? of Cres- 

 sonia with those of Phlegethontius, which attain a length of over 3 inches (88 nun.), greater than 

 that of the entire body, or tiiat of the South American sphinx (Maernslla c/iwnf/t/.^), whose 

 tongue is said by Wallace to be 9i inches in length," we see that within the limits of a single 

 family an organ like the spiral tongue may by frequent exercise be greatly enlarged and other- 



" One from tropical Africa, Macrotiila (Xanlhopan), morgani, is 7i inches long, according to Wallace (Natural 

 Selection, p. 146), though Rothschild and Jordan state that it is about 225 mm., equal to 8 inches. Revision of the 

 Lepidopterous Family Sphingida;, p. 32. 



