MEMOIRS OF THP: NATIONAL ACADEMY OF SCIENCES. 59 



pectinations line, slender. Hut. and elosely pressed to the basal l)ranehos of the next joint. (This 

 tvpe of antennfe is verj' persistent, with no exception; those of 9 , either with a sino-le pair of 

 stout, short pectinations {Adt^oci-phdla hicolor)^ or simple, without vestigial branches (Anisota, 

 Adelocephala, Syssphinx, Eacles. and Citheronia, except in C. j'rhicijxdis, in which the\' are 

 minute, teeth-like). 



Palpi usually much reduced; in Adelocephala scarcely visible, short, feeble, depressed; 

 where largest and best developed, not reaching the front (Eacles and Citheronia); denuded, 

 3-jointed (Anisota, PI. XXXVI, tigs. 10, 10a); in Eacles, 2-jointed (iig. 11). 



Maxilla? varying in degree of development even in the same genus; not united to form a 

 sucking tuV)e; in Anisota, apparently no vestige left; in Adelocephala mhangidafa, they are 

 comparatively well developed, and are as long as the filiform tip of the antenna?; in Eacles, 

 longer than in any other genus, but not visible without removing the scales; in Citheronia, as 

 long as the front of the head in the middle (PI. XXXVI, tig. 5). 



Body Sphinx-like, or spindle-shaped, thick; thorax stout; at)domen large and rather long. 



Fore wings usualh- nairow. Sphinx-like in shape in Syssphinx and many species of Adelo- 

 cephala. The costa straight, apex acute, the outer edge very oblique; either simple or scalloped 

 (as in Sraerinthus), the inner angle nearly efl'aced; or the wings become wider, the costa more 

 arched toward the apex, which tends to become square and the outer edge less oblique in Eacles 

 and Citheronia, those of Anisota being intermediate in shape. 



Hind wings also sphingoid in size and shape; short, very broad, and not reaching so near 

 the end of the abdomen as usual; in Adelocephala and Syssphinx the costa very full, convex; 

 apex rounded, outer edge somewhat excavated in S or, as in $ Anisota, of a singular triangular 

 shape, somewhat produced toward the inner angle; this characteristic especially emphasized in 

 A. t'irgmiensis. The hind wings are most normal or conventional in shape in Eacles and 

 Citheronia, where the outer edge of the wing is full and rounded. 



Venation: Fore wings, eleven veins present; the discal cell smaller than in any other 

 subfamily of the protosphingoid group; it is only about one-third as long as the wing, and very 

 narrow, especially in Adelocephala. Syssphinx, Anisota, and Citheronia. 



Vein IV,, (or sixth radial) forming a true independent vein, lieing widely detached from 

 its stalk, and situated in the middle of the extradiscal cell, i. e., just midway between veins 1\\ 

 and IV3. This liberation or detachment of vein IV., is most marked in Eacles, but less so in 

 Citheronia, yet the character is very persistent and fairly diagnostic, as nuich as any character 

 can be. 



The two discal \-eins taken together form an oblique line, which is directed outward in 

 Eacles, the posterior discal vein being directed inward in Citheronia, while the line is straight 

 in S\'s.sphinx; in Adelocej)hala Mxecta and Kuhangulata the line is regularly curved. The course 

 of these veins is peculiar and characteristic of the grouj) in Adelocephala, Syssphinx. Anisota, 

 and Citheronia. 



Hind wing: Vein II (subcostal + radial vein) is almost sinuous in Syssphinx. There are 

 invariably nine veins instead of eight (not counting I) (a diagnostic feature), this being the addi- 

 tion of vein VII; VIII being the second axillary vein. The discal cell very small; especially 

 narrow in Adelocepluda h/secfa. The discal veins taken together form an ()bli(|ue line, which 

 is curved outward, especially in Eacles. 



Vein IVo only j)artially detached, never forming a true independent vein, thus diti'eriug 

 from the Agliinie (though Aglia itself approaches Eacles in the venation of the hind wings). 



Legs long, stout, slrong, spined, the vestiture short and close, nuich as in Sphingida\ The 

 fore-tibial epiphysis well develoixnl, varying in shape from lanceolate to oval. (PI. XXXVI, 

 figs. 12-22.) 



Larva. — Body spliingiform, anal legs like those of the Spiiingid.e; head subconical, narrow- 

 ing toward the vertex: the surface smooth, not tinely spinulated with secondary spinules as in 

 Smerinthina\ The trunk segments armed with long, sharp, dorsal and subdorsal curved spines, 

 those of the prothoracic segment som(>times well developed (in the more primitive species of 

 Adelocephala and Citheronia), ])Ut usually partially atrophied. A long, sharp caudal horn; 

 between this and the tlidi-aiic horns the dorsal spines of al)fl()Miiiial se<>-mcrits 1 to 7 in the more 



