THE CANADIAN ENTOMOLOGIST. 187 



not the case, the whole surface appearing white and as though dusted over 

 with microscopic grains of tiuartz. The bosses may be studied by reflected 

 h'ght ; the primary reticulation is visible as dark but well-defined, clear-cut 

 lines when viewed under a moderate power by transmitted light ; and the 

 secondary ornamentation can be satisfactorily made out in prepared 

 sections only. Fig. 8 is a composite drawing made by combining the 

 results of all three methods. 



Other and more important differences are these: (i) Hefirici cgg?> 

 are smaller than irus eggs in the proportion of 8 to 9 (equatorial diameter), 

 and yet (2) the "hexagons" (Scudder) formed by the roughly equilateral 

 triangles of the reticulation are larger in Henrici in the pro])ortion of 5 to 

 3, and (3) the bosses are in //^//r/V/ broader in the proportion of 2 to i. 

 These facts are brought out in fig. 9 (primary reticulation Hcnrici), and 

 fig. 10' (outline irus, and part of reticulation*). Moreover (4), 'the 

 reticulation oi Henrici h far more regular than that oi ir/is, which latter is 

 often broken up by areas without or with greatly reduced bosses, and the 

 "cells" (Scudder) not arranged in hexagons. Compare figs. 5 and 6. 

 Again (5) the •' cells " of Henrici are sunken so that the lines connecting 

 the bosses are bowed inward, giving each boss the appearance of being 

 raised on a rude ])yramid. (6) In an irus egg the reticulation is continued 

 (without bosses) over the bottom, while the bottom of the Henrici egg is 

 nearly clear, transparent, and without reticulation. (7) The micropyle 

 of irus is clear, and merges almost imperceptibly with the surrounding 

 " cells."! That of Henrici (fig. 7) contains occasional refractive corpuscles 

 (nobis), and is strongly demarked from the surrounding area by the 

 rather ragged edge of the secondary ornamentation. 



(To be continued.) 



A FOSSIL CATERPILLAR. 



BY T. D. A. COCKERELL, BOULDER, COLO. 



Among the materials obtained in the summer of 1906 in the Miocene 

 shales of Florissant, Colorado, is a beautifully-preserved caterpillar. It was 

 collected by my wife at Station 14 (of Bull. Amer. Mus. Nat. Kist., 1907, 

 p. 131). It appears to belong to a distinct genus, and may be character- 

 ized as follows : 



*For a complete figure of irjts eggf see Scudder's Butterflies of the Eastern 

 U. S. and Canada. 



tFigured in Scudder's Butterflies of the Eastern U. S. and Canada, Plate 68, 

 and in the C.\NADi.\N Entomologist, Vol. XXX\'in, Plate 1 (May, 1906). 

 June, 1907 



