Ciitiulian mntoinalonbt. 



Vol. XXXIX. LONDON, SEPTEMBER, 1907. No. 



STUDIES IN THE GENUS INCISALIA. 



BY JOHN H. COOK, ALBANY, N. Y. 



IV. — Inclsalia NTPHON. 

 (Continued from page 260.) 



First Larval Instar. — The caterpillar just from its egg-shell has been 

 carefully described by others, except under the microscope it appears to 

 differ from newborn larvre of irus^ augiistus and Henrici only in its slightly 

 greater size and the darker colour. The differentiating character which I 

 gave in a previous installment* lias not borne the test of subsequent 

 investigation. The statement there made, that in iiiphon the short bristles 

 associated with the latero-dorsal series of hairs are black and compara- 

 tively conspicuous, was based on comparisons of the one living niphon, 

 which I secured from an egg in 1906 with living and alcoholic material 

 of the other species, and as the examination was made under the same 

 microscope, with the compared caterpillars side by side on the same slide, 

 it is hardly likely that I was guilty of an error of observation. However, 

 the larvfe which hatched from eggs secured this spring (1907) were com- 

 pared with living larvje of iriis and augiistus in the same manner, and the 

 notes taken read: "Latero-dorsal bristles not more conspicuous than in the 

 other species, colour darker, rather anomalous, to naked eye and under a 

 simple lens gray-green-yellow, as though the interior of the body were 

 gray-green and showed through a transparent-yellow; with two-thirds 

 objective the griseous appearance is lost, but the yellow is not so 

 brilliant as that of the compared species. Otherwise as before noted. t 

 No variation among 14 examined. Eggs from confined females, Lake- 

 wood, N. J., May 19th, 1907. 



On the second or third day after birth the appearance of the larva 

 begins to alter ; the dorsal area shows two dull longitudinal stripes, and 



'Canadian Entomologist, Vol. XXX\'III, No. 6 (June, 1906), p. 182. 



tA complete set of newborn larva; has been preserved, and a full discussion 

 of the specific characters, with illustratious, will, it is hoped, be given in a second 

 series of studies in the genus, dealing with the comparative anatomy of the 

 various stages to follow these outlines of the life-histories. 



