1865.] 37 



relations which the sub-family Geratovampailx (to which the genera 

 Cifhf'ronia Hiibn. and Kacles Hlibn. belong) bears to the Sphingid 

 genus Geratomia Harris, and to the Sphimjidse generally, as in similar 

 instances, we divest ourselves of the idea that we have to do with a so- 

 called '"connecting link" between two distinct Families, and agree, 

 that, as is the case in Zoological Orders, Analagous Types may exist 

 through which lepidopterous Families express in their component 

 generic groups a certain conformity with the leading characters of a 

 distinct femily, while retaining the essential form proper to their own, 

 and without losing true affinity in producing foreign analogy. It is 

 evident that it is the larva of Geratomia which mimics the Geratocom- 

 padse, and not vice versa, since the smooth larval form of the Sphin- 

 gidae borrows a character which is usually developed in the Bomby- 

 cidae, though peculiarly exaggerated in the sub-family which contains 

 Anisoia, Adelocephala, Gttheronia and Eacles.* 



Misled by an analogy of habit with the Humming Birds, the authors 

 of the "Wiener Verzeichniss " f have classed the Sphingidae as the 

 highest family of the Lepidoptera, and have considered that in this 

 analogy a sufficient value is demonstrated to allow of their juxta-posi- 

 tion with the Aves.| An inspection of their illustrated Frontispieces, on 

 which the feeding Vertebrate and Articulate are depicted side by side, 

 teaches in a striking manner the value of the philosophical distinctions 

 to be drawn between, and the ideas involved by, the terms "Analogy" 

 and " Affinity." 



I give here a few remarks and a generic description drawn from cer- 

 tain members of this Family found within the limits of the United 

 States and Canada. 



« I have stated (Proc. Ent. Soc. Philad., p. .320, 1865) that the larva of Cera- 

 tomia simulates that of tt'iAeronta.- in a greater degree, however, it simulates 

 thsit oi Eacles, belonging to the same sub-family, in the position, shape and 

 consistency of the dorsal horn-like tubercles on the anterior segments. The 

 imago of Eachs, however, is much less S2jhinx-like than that of atheroma. I 

 have taken the larva of Eacles imperialis on the ''gum," Liquidamhar styra- 

 ciflua, " beech," Fagus ferruginea, and " horse-chestnut," ^sculus hippocasta- 

 num. 



t " Systematisches Verzeichniss der Schmetterlinge der Wienergegend." 

 Wien, 1776. 



X und in dieser Ordnung die Gattung der Honigsauger (Trochilij die 



letzte stehen konnte, wie ungezwungen (1) wiirden sich unsere Abendschmet- 

 terlinge daranschliessen. W. V. p. 28. 



