NOVITATES ZOOLOGICiE XXV. 1918. 395 



A PKOVISIONAL ARRANGEMENT OF THE DIOPTIDAE. 

 By LOUIS B. PROUT, F.E.S. 



IN arranging the material in the Joicey collection and the Tring Museum 

 belongmg to the interesting Lepidopterous family Diopiidae, I have found 

 it necessary to adopt some provisional system of classification, since apparently 

 none at present exists. And although I have not been able to go deeply into 

 the structure, or even to examine all the known species, I think I have noted 

 sufficient clues and placed satisfactorily sufficient of the species and groups of 

 species to warrant my publishing the results thus far obtained, if only in the 

 hope of inducing other workers to follow them up. For myself, I am too much 

 preoccupied with the Geometridae and see little likelihood of pursuing this other 

 line of research. 



On the family in general, particularly with regard to its differentiation 

 from the Geomelridae, I have contributed a few notes in Wytsman's Genera 

 Insectormn (fasc. 103, p. 8 ; 104, p. 2). I may add that Forbes {Psyche, xxiii. 191) 

 observes that " The Dioptidae show no tympanum of any kind and will make 

 a first exception to the rule that uniordial hooks on the prolegs are co-ordinated 

 with a tympanum of Arctiid or Noctuid type." Dyar {Journ. N.Y. Ent. Soc. 

 iv. 69) inclined to regard Dioptidae as ancestors of Pericopidae (New World 

 Aganaidae = Hypsidae, according to Hampson's system), while treating the 

 true " Hypsidae " as " a low Noctuidous type." I believe both Pericopidae 

 and Aganaidae to be non-specialised Arctiids, and the resemblances between 

 Dioptidae and Pericopidae to be purely mimetic, just as are those between 

 Dioptidae and Lithosiids or many others. In his " Additional Notes on the 

 Classification of Lepidopterous Larvae" {Tr. N.Y. Acad. Sci. xiv. 49-62) Dyar 

 provides (p. 56) a tentative synopsis of the " Superfamily Noctuina " in which 

 the two families in question find themselves, from my point of view, in better 

 company, though we have still very much to learn on the phylogeny. 



The following characterization of the family will sufiice for my present 

 purpose, and will save repeating the " constants " in diagnosing individual 

 genera. 



Constant Characters. — ^Eye naked. Pali^us well developed, more or less 

 upcurved, terminal joint not elongate. Tongue fully develoj)ed. Legs fully 

 developed ; hindtibia with all spurs. Abdomen without " tympanum." Both 

 sexes winged, the wing-margins smooth. Frenulum developed. 



Forewing with areole wanting, all the subcostals present, SC from cell, 



gQ3-5 stalked, R'' not connate with R^* SM' wanting. Hindwing with C not 



angled at base, free from SC, SC^ stalked with R', R' well developed, never 

 connate with R' *), SM' obsolete,! SM^ reaching hindmargin near tornus. 



Variable Characters. — Face, palpus, pectus, and femora with appressed 

 scales or moderately (rarely densely) hairy. Antenna in 3 bipectinate or 

 ciliate. Wings more or less elongate, sometimes in large part diaphanous. 



* Normally central, but occasionally — as in the Geometridae — driven back to near R-* by a 

 strong posterior prolongation of the cell. 



t Comstook has found (negligible) traces of it in Phryganidia. 



