Ixv 



4. Is Pseudopontia a Pierid, or What ? by Dr. R. J. 

 Tillyard. 



[From the letter accompanying Dr. Tillyard's note.] 



Caivlhron Institute, 

 Nelson, N.Z. 



March 6, 1922. 



After recovering from my accident, I went for a trip to 

 Australia last October, and took two specimens of Pseudo- 

 pontia with me for my friend Mr. Gr. A. Waterhouse. He 

 examined them and declared at once that they were certainly 

 not Pieridae, but he would not give detailed reasons; only 

 said that they were extraordinary beasts, not belonging to 

 any known family. I concurred at the time, thinking he 

 must surely be right, but before writing to you, I set down 

 carefully the best definition of a Pierid I could find, and 

 tested Pseudopontia by that definition. I was surprised, 

 and rather pleased, to find that this careful test shows your 

 butterfly to be in every respect what it looks, viz. a true 

 Pierid. The argument is set forth fully in another sheet 

 enclosed herewith [jjrinted below]. 



I would say that this butterfly is the most highly specialised 

 Pierid I have yet set eyes on, and I anticipate that its larva 

 and pupa will show true Pierid characters. 



[In the account printed below Dr. Tillyard uses his new 

 notation developed from that of Comstock and Needham. 

 By means of the numbers in parentheses his terms can be 

 followed on figs. 7 and 8 of Plate B.] 



To answer the question " Is Pseudopontia a Pierid? ", we 

 have first of all to ask : What constitutes a Pierid ? Leaving 

 out of account the early stages, which are unknown, but 

 which, if knov,'n, would certainly solve the problem, we may 

 define a Pierid by the following characters : — 



Antennae close together at bases. Front pair of legs 

 perfect in both sexes. Hind tibiae with terminal pair of 

 spurs only. Fore-wing with one or more branches of Rs 

 (7-9) stalked beyond the cell. Hind-wing with precostal 

 spur present, but no closed precostal cell ; also with vein 

 3A (la) present. 



Applying these tests, we find that Pseudopontia possesses 



PROC. EiSTT. SOC. LOND,, V, 1922. E 



