40 MEMOIRS (tF THE NATIONAL ACADEMY OF SCIENCES. 



Of course merely nicliiiientarv organs niu}' either renuiin in an indifferent state, or by 

 change of hal)it or during metamorphosis become develoi)pd and actively function. 



X. ORIGIN OF THE SYSSPHINGINA AND ALSO THE SYMBOMBYCINA, 

 FROM THE NOTODONTIDiE. 



The family Notodontida- is divisible l)v Iar\al characters into two groups of sultfamilies, 

 characterized bj' the presence in the larva (1) of simple unisetiferous tubercles (Notodontinai, 

 Heterocampina*. and Cerurina;) and ('■2) of warts giving rise to .several hairs, more than one at 

 least, or to tufts of hairs (Icthyurina% PygEerinfe. and Apatelodina?). It seems evident that each 

 of the.se two notodontian groups has given origin to a subphylum or superfamily, rather than 

 that the whole family has given rise to one alone, i. e., the Saturniide.s. These two gi'oups we 

 would designate as the SysuphingiiKt and Symljonih/chat. (See fig. 4. p. 46.) 



(>ri</i)i of the ■'<u])erf(imily Syinhonihycina. — I was led to this conclusion by a suggestion 

 tlirown out by Doctor Dyar in 1896." and again in 11*01, * when he shows the relations of the larval 

 arnuiture or warts of the Icthyuriua? (Melalopha?) to that of the Eupterotidiv, Liparida?, Lasio- 

 campidre, etc. In his phylogeny published in 1896, he derives the following live families from 

 the hairy Notodontidic, i. e.. Eupterotidw, Lymantriidii? (Liparida?), Bombycida'. Lemoniida^, 

 and Lasiocampida^, the last l)eing in his view the latest and mo.st specialized family. Following 

 the suggestion of Mr. Schaus, Doctor Dyar in 1896 included the genus Apatelodes in the Eupter- 

 otida?, a.s also "the other hairy Notodontians, ]\lelalo])ha, Datana, and Phalera." but afterwards 

 (1901) concluded that this arrangement is contradicted by the form of the eggs (p. 418). 



Having been led by Doctor Dyar s suggestions to examine the armature of tlie hairy 

 notodontians, and to study the head and other characters in abdominal segments 8-10, I am 

 disposed to accept his views as to the origin of hairy larva' of the families named from the 

 Notodontidffi with multisetiferous warts. Even where the fully fed larva is smooth-bodied, 

 without any hairs or only minute ones, as in Bumhy.r mori and Endromh vesicoJoru. as well as 

 the Brahma'ida\ the young larva? are born with multi-setiferous warts, the .setse l)eing long, tine, 

 and hairliko. In fact my investigations on the larva have led me to observe that there is an 

 extensive group of families which are more or less related to the Bombycidiv in the restricted 

 .sense. This group, or superfamily, I have called the Symbombycina, the word referring to those 

 families all connected bv ties of blood, or kinship, with Bomhy.v inorL The old terms Bombyces, 

 Bombycidfe, formerly applied to any moths in which the maxilla? were aborted and con.sequently 

 from disuse the head became small, the wings less exercised so that one or more veins became 

 ati'oyjhied, must now be restricted to this group with its entirely new name, Symbombycina, i. e., 

 all those families affiliated witli tlic Bomliycida\ as now restricted to the genus Bombyx and its 

 allied genera. 



This superfamily has very plainly descended b}- divergent evolution from the hairy Noto- 

 dontidfc, i. e., the groups Ichthyurina and Apatelodina. the former being the more ancestral 

 or primitive one. 



On the other iiaii<l the Cei'atocampida\ Hemileucithe. .Saturniidie. and ."^phingida have 

 evidently descended from the smooth-bodied, often more or less humped Notodontida. i. e., the 

 Notodontiiuv and Hcterocampina?, and this great group 1 regard as a supi>rfamily. For this 

 group I have ])r()posed the name Syssphingina, because it comprises, besides Sphingida, the 

 ancestors or primiti\(' foiins which gave I'ise to that highly specialized family, the families 

 mentioned evidently fornung a separate suV)phylum of Lepidoptera. 



Tile stei)s which led me to consider the Notodontida' as having been the common source of 

 these two great superfamilies may now be stated. 



Doctor Dyar has shown the I'esemblances. or rathei- close aflinity, of tlie haii'v notodon- 

 tians to the Liparida'. etc.. as proved by the nature and ^situation of the hair-ljearing or multi- 



"I'roc. Boston .Society Nat. Hist., XXVII, p. 139. 

 ''I'roc. Ent. Soc. Wasli., IV. p. -lis. 



