( 105 ) 



species took place witliiii Ci'ratoma, while l.wqrdmnm. reiuaiucd represented only 

 by one species. Now, if thei'e are otlier forms to be discovered wliich are furtlier 

 developments from Cerafomia and Jsoyramiiin, it is obvious, judging from tlie 

 general tendency of evolution among tlie Acherontiinae, that the next step beyond 

 Isognimma would be represented by an insect with spiny tiliiae, but without 

 ])nlvillus, and that the next step bej'ond Ceratomia would be a form without 

 pulvillns as in Ceratomia, but with spiny tibiae ; the two forms, therefore, thus 

 resulting, although not of the same origin, would be identical in tliose characters. 

 In such instances the classifier who endeavours to give a classification based upon 

 blood-relationship has to be careful. There are many traps for the classifier who 

 is merely guided by the presence or absence of a certain character. Similarity and 

 blood-relationship are not identical conceptions. Spinosity of the legs and reduction 

 in their length, reduction of parouychium, pulvillus, tongue, and palpus, appear- 

 ance of fasciculated ciliae on the ? -antennae recur in many instances among 

 Acherontiinae and Ambulicinae in phylogenetically widely separated forms. Only 

 by closely following the various lines of development is it possilile to distinguish 

 between what is similar and what is related. 



78. Isogramma hageni. 



Cemtmnla luvjeni Grote, I.e. ii. p. 149 (1874) (Texas) ; id., I.e. ii. p. 227. n. 47 (1875) ; Butl., Tram. 



Zuol. Soe. Loncl. ix. p. 621. n. 2 (1877) (Texas) ; Maass., SiHt. Enl. Zelt. p. IB (1880) (not 



a Cerat., but prob. a Daremma) ; Grote, Ptqiilia ii. p. 170 (1882) ("Kansas" err. loc.) ; 



Smith, Tram. Amer. Ent. Sue. xv. p. 204 (1888) (Texas). 

 Daremnia hugetii Grote, Bull. Buff. Soc. N. Se. iii. p. 224. n. 49 (1877) (Texas) ; id., Papilio iii. 



p. G5 (1883) (Texas, not Kansas) ; Kirby, Cat. Lep. Bet. i. p. 684. n. 2 (1892) (Texas). 

 Sphinx hageni, Strecker, Lcp. Rhop. Het. p. 127. t. 14. f. 6 (1878) (Texas ; desor. of larva) ; Riley, 



Rept. U. St. Dept. Agr. p. 193. t. 12. f. 2 («., I.) (1882). 



The forewing has a yellowish green tint, which is not present in Ceratomia 

 umhilosa, with which a casual observer might confound the present species. 

 Hab. Texas. 

 In the Tring Museum 1 c?, 2 ? ?. 



XXVII. CERATOMIA.— Typns : amyntor. 



Afiriun Hiibner (iion id., 1822), Sainml. Ex. Schm. (1824?) (nom. indescr.). 



Ceraloinia Harris, in Sillim., Journ. Sci. Art xxxvi. p. 293 (1839) (type : amijnlnr). 



M'jcrosila Walker, Lid Lrp. Ins. B. J/, viii. p. 199 (1856) (partim). 



Daremma id., I.e. p. 231 (1856). 



Sphinx, Grote, Proc. Ent. Soc: Philad. v. p. 72 (1865). 



Diludia id. {nan id., 18C5), Bull. Buffalo Sne. N. Sci. iii. p. 224 (1877). 



Pneudniti^hinx, Butler {nnn Burmeister, 1856), Trans. Zool. Sue. Lnnd. ix. p. 629 (1877). 



S ? . Tongue, palpus and eye reduced; antenna of ? not andromorphic ; tubercle 

 of labrum with sharp edge. Tibiae unarmed ; foretibia short, first segment of fore- 

 tarsns not essentially different in length from second, armed with three or four long 

 stout spines externally, externo-apical spines of segments 2 to 4 not obviously 

 prolonged; midtarsus without comb; pulvillus absent; paronychium present with 

 one lobe on each side. 



Larvae very dififerent in the three species. The larva of C. iindulosa represents 

 a more ancestral type than those of the two other species. The divergency in the 



