MEMOIRS OF THE NATIOXAL ACADEMY OF SCIENCES. 57 



the clypeiis, the cpicninium and occiput being very short and .situated behind the insertion of the 

 antenna. The surface of the clypeus or front is flat, as in all the saturnian moths, owing to 

 the absence of a functional tongue; in Syssphinx the lower edge forms a knob-like protu))erance. 

 The eyes rather large, globose. Antenna of S almost invariahly bipectinated, either on the basal 

 half or tiasal three thirds or three fourths, or to the end; with about 18 to 25 double pairs; the 

 distal pectinations of each joint nearly as long as the basal ones, and both generally densely 

 ciliated; they are sometimes plumose. In the 9 either simple, subsimple, or with short, distinct 

 pectinations, only a single pair to each joint. Labial palpi in general large and stout, sometimes 

 (Arsenura) passing beyond the front; usually 8-jointed, sometimes 2-jointed (Eacles), or Imt 

 1 -jointed and difficult to distinguish from the hairs of the front and sternum. They are large 

 and Sphinx-like in Agliinse, especially in Arsenura, where the third joint, usually buried in the 

 hairs of the end of the second joint, is distinctly seen. Maxillaj in many genera sufliciently 

 developed to be visible, but even then small, weak, the two halves separate, very slender, and 

 evidently not functioning, unless slightly so in Citheronia, where the two maxilla? are united for 

 about half their length to form the tongue. In Anisota there are no recognizable vestiges of a 

 tongue. 



Body robust, spindle-shaped, or fusiform, or in general Sphinx-like; the thorax thick, and 

 the abdomen long, conical, and when the lateral claspers are large, as in Citheronia and 

 S3'ssphinx and certain Adelocephala?, the dense vestiture on them forms lateral terminal tufts; 

 the abdomen is most conical in genera such as Arsenura and Dysda;monia. the vestiture l)eing 

 closely cropped; in some genera the vestiture of the thorax is long, dense, and shaggy. There 

 is I'arely a prothoracic collar, one being slightly developed in Arsenura and Dysdivmonia. The 

 patagia are rarelv distinct!}- apparent, owing to the dense, long vestiture of the thorax. 



The fore wings vary greatly in shape, in the more tvpical forms being in Ceratoeampidte 

 sphingiform, the costa straight, the apex acute or subacute, the outer edge very oblique, or they 

 ma}' be very broad as in Arsenura and Dysdamonia, or closely similar in shape to those of the 

 saturnians (Nudaurelia, Gynanisa. etc.). 



The hind wings equally vary from their normal pi'oportions, the apex })eing rounded and 

 the outer edge entire, or they may be Spliinx-like. or variously angulated or tailed, as in Dysdie- 

 monia, in Urota, and Cercophana. 



Venation: There are in the fore wings invarial)ly eleven veins present, and in the hind wings 

 eight or nine (nine invariably in the Ceratocampinse, seven in Eudfemouia), there being no vein 

 VI. It also diti'ers ivom that of the saturnians in the discal cell being invariably closed by the 

 discal veins. 



The discal cell is always closed, the cross vein, i.e., the two discal veins (anterior and poste- 

 rior, or "discocellulars") united to form a continuous line, which is either bent, more or less, 

 outwai'd or inward, or regularly curved outward or inward, or directed obliquely outward 

 and inward. The discal cell is often small, in the typical members of the family (Ceratocam- 

 pinie) very small, short and narrow, and not extending to the middle of the wing, but in some 

 cases, in Poh'thysana, etc., it extends beyond the middle of the wing (along the cubital or vein 

 IV), so that the veins beyond it may be very short. 



Hind wings, with eight veins; the first or anterior discal vein is very oblique, directed inward 

 and backward. 



E(/</. — Those of the Ceratocampinie differ from those of the Saturniida' in l)eiiig low. some- 

 what flattened, broad, elliptical, not cylindrical; the shell is thin and tough, parchment like, 

 while the sculpturing is partly ()l)solete. The eggs of the Agliina? and Bunasinaj are not well 

 known. 



Larva. — iii the larva after stage I, as well as in subsequent stages, the setiferous tubercles 

 are solid and ciiitinized, forming a stout, long spine or horn (never polysetose rounded knobs or 

 button-like tubercles as in Saturniida?). in some cases bearing a fine seta at the end. The suranal 

 plate is armed with bosses, or in some cases with horns, with the result that the armature of the 

 family in general is more formidable than in any other group of Lepidoptera. The anal legs or 

 claspers are large, squarish, and solid. There is, with a few exceptions (Anisota). a caudal horn 



