AND THEIR TRANSFORMATIONS. M5 
The caterpillar is green, with a pale, angulated row of dorsal spots, and a central brownish line. It feeds. 
according to Haworth, on grasses, but Esper figures it upon the wild strawberry. It appears in this state in the 
months of April and June. 
In the Entomological Magazine (vol. ii. p. 515) Mr. Newman endeavoured to prove that this species and 
7 oe © » ~ . 7 
the two following ‘“‘are but one species. Specimens taken at Ramsgate, Dover, Hythe, Hastings, Rye, 
Brighton, Worthing, Little Hampton, Chichester, Portsmouth, Isle of Wight, Dorsetshire and Somersetshire, 
exhibit the “typical form” of the species (as described above) ; at Birmingham, Worcester, and Shrewsbury, 
‘an evident change has taken place, the band of rust-coloured spots has become less bright ; at ‘Manchester 
these spots have left the upper wing almost entirely ; at Castle Eden Dean they are scarcely to be traced, and a 
black spot in the centre of the upper wing becomes fringed with white ; in some specimens it is quite white ; 
the butterfly then changes its name to Salmacis. We proceed further northward, and the black pupil leaves the 
eyes on the under side, until at Edinburgh they are quite gone ; then it is called Artaxerxes.” Mr. Stephens does 
not, however, agree with Mr, Newman in this respect, stating that “ his definitions do not accord with my series 
of specimens of the three insects obtained from nearly every one of the localities enumerated by him.” (Illustr. 
Haust. 4, p. 382.) Boisduval also gives the Artaxerxes as distinct, stating that its fore wings are proportionably 
longer than those of Agestis ; to which I may add that the relative position of the spots (which seems to me in this 
genus to afford a good specific character) is different in the two species, especially on the under side of the upper 
wings. 
DESCRIPTION OF PLATE XXXVII. 
Insects.—Fig. 1. Polyommatus Salmacis (the Durham Argus B.). 2. The female. 5. Showing the under side. 
ee Fig. 4. Polyommatus Artaxerxes (the Artaxerxes B.). 5. The female. 6. Showing the under side. 
Prants.—Figs. 7 and 8. Ononis procurrens (trailing Rest-harrow). 
The insects on this plate are all figured from the cabinet of Mr. Stephens. I have placed these two species together to enable the collector 
to compare them, as they have been supposed by some to be merely variations of one species. In Salamacis it will be seen the female is 
sometimes without the white mark, which is more constant in Artaxerxes, and Salmacis has more frequently a slight indication of an orange 
border on the fore wings. On the under side Artaxerxes is without the black pupil in the pale spots, which is pretty constant in Salmacis. H.N.H. 

SPECIES 14.—POLYOMMATUS SALMACIS. THE DURHAM ARGUS BUTTERFLY. 
Plate xxxvii. fig. 1—3. 
Synonymes.—Polyommatus Salmacis, Stephens, Ilust. Haust. vol. tii. p. 235. 
Wood, Index Ent. t. 3, p. 73, ¢ Q, and fig. 12. Duncan, Brit. Butt. pl. 34, fig. 2 and 3. 
This species is intermediate between Agestis and Artaxerxes, and varies in the expanse of its wings from 1,4 
to 14 inches. The upper side of the wings is of a silky blackish brown colour, with a black spot at the extremity 
of the discoidal cell in the males, and a white one in the females, which is, however, sometimes obsolete, 
especially in the lattersex. There is also a row of submarginal fulvous spots in the hind wings, which sometimes 
also extends along the margin of the fore wings, but it is occasionally almost obsolete in the male. The fringe is 
white, with slight brown marks at the base. The under side of the wings is of a brownish grey, the anterior 
wings having a white spot at the extremity of the discoidal cell, succeeded by a curved row of similar spots, each 
marked in the centre with a dusky point ; there is also a submarginal row of orange spots bounded above with a 
dusky crescent, and marked beyond with a dusky spot surrounded with white, the extreme margin being marked 
