460 ENTOMOLOGICAL NEWS. [DeC, 'll 



rlt. right lateral trachea. I 2nd and 8th abd. segs., 



rvrt, right ventral rectal trachea. > respectively. 



sa, superior appendages (cercoids) I /, trachea. 



of imago. j wp, wing pads. 



sp. I, sp. 2, sp. 8, spiracles of 1st, | I-X, abdominal segments i to 10. 



Plate XVIII. 



Figs. I, 2. Larva No. 55, placed on the netting out of water for 

 comparison. 



Figs. 3-7- Larva No. 55, transforming April 6, 1910. Figs 3-5 show 

 the tracheal linings being pulled out of the right thoracic spiracles as 

 white lines. 



Fig. 8. Larva No. 59, transforming April 4, 1910, 9.05 A. M. (For 

 continuation of this series see Plate XIX). 



Fig. 9. Ventral surface of metamorphic exuvia No. 55. 



Fig. 10. Dorsal surface of metamorphic exuvia No. 57. After 

 transformation the exuvial coverings of the gills as they dry become 

 shriveled. In this case special care was taken to spread them out on a 

 piece of paper that they might dry in approximately natural shape 

 attached to the paper. 



Fig. II. Larva No. 57 jihotographed ali\e in water, March 2, 1910. 



Pl.ATK XIX. 



Figs. 1-7. Larva No. 59, transforming April 4. 1910. Between the 

 taking of photographs 3 and 4 the netting was shifted to bring the 

 imago into side-view. 



Fig. 8. Metamorphic exuvia of No. 59 after transformation, April 



4, 1910, at 10.46 A. M. ; 20 mm. long. 



All figures on Plates XVIII and XIX from photographs by Amelia 



5. Calvert. 



The Peckham Collection of Spihers. — The Public Museum of the 

 city of Milwaukee, Wisconsin, has recently received a donation of 

 great value. Tliis is the entire collection of spiders, chiefly Attida?, 

 from all parts of the world, of Dr. George W. Peckham. whose 

 work on Solitary Wasps and Spiders is so well known. The collec- 

 tion includes many thousands of spiders, among them many species 

 determined by Simon. The types, of which a few are still in the col- 

 lection, will be sent to Cambridge, where the rest of Dr. Peckham's 

 have been sent. Dr. Peckham included his entire library on Arach- 

 nida in this donation. He expects to leave shortly for Central Ameri- 

 ca, probably Guatemala, where he will stay for six months. 



R. A. MuTTKOWSKi. Milwaukee, Wis. 



