60 



metathorax, with the loss of a well-developed maxillary palpus in 

 families above the Nepticulidae. Chapman described the genus Graci- 

 laria as possessing maxillary palpi, and in two species, sassafrasella 

 and negundclla, a structure has been found (Figs. 45, 47) which may 

 be the maxillary palpus ; but there never is a distinct, oblong piece lying 

 caudad of the eye-piece as is usually the case when the maxillary palpi 

 are present, and of all the species of the superfamily examined these 

 two were the only ones in which there was any doubt as to its absence. 

 The head is in most families either produced into a prominent projec- 

 tion or there is a heavily chitinized cutting plate near the cephalic mar- 

 gin on the ventral surface. The prothorax has a tendency to become 

 shorter on the median line and longer on its lateral margins, so that 

 each half is triangular. In such cases the length along the lateral 

 margin is about four times the length on the median line.- In the more 

 generalized forms the prothorax ,is more like the rectangular type 

 found in the Tineoidea, but it is depressed or sunken, giving it a neck- 

 like appearance. The metathorax still retains its primitive condition, 

 and is usually more than half the length of the mesothorax. In nearly 

 all of the families the wings are long in proportion to the body, and in 

 the majority they are about two thirds its length. The bodies of most 

 of the families included here retain the generalized type found in the 

 Eriocraniidae with a slight depression near each lateral margin in the 

 region of the spiracles. The spiracles are usually small, circular, and 

 slightly produced, appearing tubular. The Lyonetiidae seem to be an 

 exception to almost every rule. They have no free segments, the 

 appendages are all soldered to the body, and there are no spines visible 

 on the abdomen. They seem to be more nearly related to the Buc- 

 culatrigidae than to any other family, although there are strong rea- 

 sons for considering them related to the Phyllocnistidae. The follow- 

 ing table will serve to separate the families of Gracilarioidea : 



a. Maxillary palpi well developed and extending along the caudal margin 

 of the eye ; spiracles visible on the first abdominal segment. 



Nepticulidae. 

 aa. Maxillary palpi never well developed, and if present never extending 



as an oblong piece along the caudal margin of the eye. 

 . 1). Antennae never extending more than half the length of the wings; 

 lahrum very long and lobe-like, extending down over the labial 

 palpi for about one fourth of their length; spines on the dorsum 

 of the abdomen very fine and not easily distinguished. 



Heliozelidae. 



bb. Antennae always extending at least three fourths the length of the 



wings, and usually equaling them in length or extending beyond 



their caudal margin ; labrum never long and lobe-like and never 



