40 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Of course merely rudimentary organs may either remain in an indifferent state, or by 

 change of habit or during metamorphosis become developed and actively function. 



X. ORIGIN OF THE SYSSPHINGINA AND ALSO THE SYMBOMBYCINA, 



FROM THE NOTODONTID^E. 



The family Notodontidw is divisil)ie by larval characters into two groups of subfamilies, 

 characterized ))y the presence in the larva (1) of simple unisetiferous tubercles (Notodontinw, 

 Heterocam]3ina% and Cerurina?) and {'A) of warts giving rise to several bail's, more than one at 

 least, or to tufts of hairs (Icthyurinte, PygiBrin^, and Apatelodinte). It seems evident that each 

 of these two notodontian groups has given origin to a subphylum or superfamily. rather than 

 that the whole familj' has given rise to one alone, i. e.. the Saturniidcs. These two groups we 

 would designate as the Syssphinghin and Syynboinhycina. (See fig. 4. p. 4*!.) 



Origin of the Kuperfmnih/ Symhoinhycina. — I was led to this conclusion by a suggestion 

 thrown out by Doctor Dyar in IS'.tO," and again in 1901,^ when he shows the relations of the larval 

 armature or warts of the Icthyurina; (Melalophte) to that of the Eupterotid», Liparida?, Lasio- 

 campidie, etc. In his phylogeny published in 1896, he derives the following five families from 

 the hairy Notodontida% i. e., Eupterotida^, Lymantriid» (Liparida?), Bombycida'. Lemoniida-, 

 and Lasiocampida?, the last being in his view the latest and most specialized family. Following 

 the suggestion of Mr. Schaus, Doctoi' Dyar in 1S96 included the genus Apatelodes in the Eupter- 

 otida>. as also "the other hairy Notodontians. ]\Ielalop]ia. Datana. and Phalera," but afterwards 

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



Having lieen led V)y Doctor Dyar's suggestions to examine the armatui-e of the 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 larv;e of the families named from the 

 Notodontida' with nudtisctiferous warts. Even where the fully fed larva is smooth-bodied, 

 without any hairs oi' only minute ones, as in Bomhy.i' iiivri and Eiidroiiiif< vt'xicoJora, as well as 

 the Brahma?idie, the young larva? are born with nudtisetiferous warts, the setie being long, tine, 

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

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

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

 families all connected liy ties of blood, or kinship, with Bo)iJ)y:r mori. Tiie old terms Bombyces, 

 Bombycida?, formerly applied to any moths in which the maxilla? were altorted and consequently 

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

 atrophied, must now be restricted to this group with its entirely new name, Symbom))ycina, i. e., 

 all those families affiliated with the Bombycida\ as now restricted to the geiuis Bombyx and its 

 allied genera. 



This superfamily has very plainly descended l>y divergent evolution from the hairy Noto- 

 dontida, i. e., the groups Ichthyuriiue and Apatelodinie, the former being the more ancestral 

 or primitive one. 



On the other hand the Ceratocampidw, Hemileucida?, Saturniida^. and Sphingidse have 

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

 Notodontina^ and Heterocampinie, and this great group I regard as a superfamily. For this 

 group I iiave proposed the name Syssphingina, because it comiirises, Ijesides Sphingida\ the 

 ancestors or primitive forms which gave rise to that highly specialized family, the families 

 mentioned evidently forming a separate subphylum of Lepidoptera. 



The steps which led me to consider the Notodontidte as having l)een the conuiion source of 

 these two great superfamilies may now be stated. 



Doctor Dyar has shown the i-esemblances, or rather close affinity, of the hairy notodon- 

 tian.'? to the Liparidie, etc., as proved b\^ the nature and situation of tine hair-bearing or multi- 



«Proc. Boston Society Nat. Hist., XXVII, p. 139. 

 ''Proc. Ent. Soc. Wash., IV, ix 418. 



