May iSqS ] 



PSYCHE. 



213 



been known to collectors for some time 

 a curious larva resemliling the excre- 

 ment of birds. It is found on the young 

 tender leaves of the hickory and butter- 

 nut in May and disappears by the end 

 of that month, not to reappear till the 

 following season. The larva is solitary, 

 though when abundant, several may 

 occur on one leaf. It is nearly footless, 

 the short feet being only feebly func- 

 tional and the larva wriggles around 

 very like a Lyda when out of its web. 

 It rests by curling around a portion 

 of leaf or stem in a single spiral and 

 only spins a few inconspicuous threads 

 of silk. It lives freely exposed, pro- 

 tected, doubtless from birds by its resem- 

 blance to a noxious object. It is very 

 unusual for saw fly larvae to be highly 

 specialized enough to mimic particular 

 objects ; but in this case the resemblance 

 is remarkably exact, as New York col- 

 lectors will testify. 



Mr. W. H. Ashmead, in a paper en- 

 titled " a synopsis of North American 

 Xyelidae," read before the Washington 

 Entomological society in Dec, 1897, 

 described two new genera and gave a 

 generic table of this group. He has 

 kindly furnished me with an advance 

 copy of this table which is given below. 



Pleuroneura aviingrata n. sp. ? Shining 

 blue-black, submetallic. Labruin emarginate, 

 w-ith a terminal white line and pair of large 

 round Avhite spots; palpi partly whitish. 

 Joint and extreme base of posterior femora 

 and last four joints of posterior tarsi white. 

 Abdomen and legs shining, head and thorax 

 dull. Nervures black, \yi,ngs nearly hyaline, 



a trace of smoky bordering the veins of fore 

 wings. Hind tibiae hairy and with six long 

 spurs. Length 13 mm.; expanse of wings, 

 29 mm. 



Lai-va. Last four stages observed. 



SUige, width of head o.S mm. Head shin- 

 ing brown. Body shining brown dorsallv, 

 milk white subventrally, setiferoiis tuber- 

 cles black, not very large, two transverse 

 roAvs per segment in dorsal aspect, three in 

 lateral view. The segments are 4-anniilate, 

 a row of four or five tubercles on each side 

 of second (spiracular) and third annulets, a 

 half row of three tubercles on the lateral 

 portion of the fourth annulet; subventral 

 folds with scarcely distinguishable rudimen- 

 tarj- tubercles. Legs colorless; a narrow ob- 

 scure white dorsal line. Feet all unusually 

 small ; thoracic ones black ringed; abdominal 

 ones on joints 6-12 and 13; above the anus 

 a pair of low conic setiferous -warts. The 

 tubercles usually have two setae each. 



The larva wriggles over the leaf when it 

 wishes to move, using the feet poorly. 



Next stage. Head 1.5 mm. wide, shining 

 brown, eye and jaws black. The white color 

 formerly confined to the subventral region is 

 now present also as dorsal patches between 

 joints 4-5, 5-6, 1 1-12, and top of joint 13 pos- 

 teriorly. Tubercles brown except the two 

 lower of the anterior row which are still 

 black. Otherwise as before. 



Stage before last. Width of head 2.1 mm. 

 Mucli the same but the brown and wliite still 

 more mottled; a broken white dorsal line; 

 nearly all the dorsum of joint 5 white. 



Last Stage. Head rounded, dark brown, 

 shining.shading paler in the sutures of mouth 

 parts; width 2.5 mm. Antennae brown, pale 

 ringed, palpi black. Thoracic feet black at 

 base; then pale with testaceous rings. Seg- 

 ment indistinctly 4-annulate, the tubercles 

 watery, concolorous and obscure, nearly ob- 

 solete and difficult to distinguish. Dorsum 

 shinning olivaceous brown ; a broken narrow 

 white dorsal line; a white patch on joints 3, 

 4, on 6 centrally to 11 centrally, patches on 12, 



