128 THE ENTOMOLOGIST. 



type than ours, especially the var. utahensis, Hy. Edw., which has 

 pale orange secondaries. C. parthenos is another nearly-allied 

 form, which I find in Western Custer Co., Colorado, at 8400 

 feet alt. (I have to thank Mr. H. Strecker for the identification 

 of this). 4. Zygcsna lavandulce lutescens has been found at 

 Cannes (see Entom, xxi. 211). For another example of red and 

 yellow forms, see G. M. Dodge on (Edipoda coraUipes (Can. Ent., 

 1876, 101). 



(e.) Teras oxycoccana is ash-grey, but the dimorphic form 

 malivorana of Le Baron is orange. This dimorphism is without 

 reference to food or sex. Similar phenomena occur in many 

 British species, of which I have received full and interesting 

 details through the kindness of Mr. J. W. Tutt. Teras (Rhacodia) 

 caudana has two forms, which are neither sexual, seasonal, nor 

 phytophagic. Mr. Tutt adds, " With regard to the other Tortrices 

 it is a wide question ; and when an extensive series is obtained I 

 believe many dimorphic species become polymorphic, i.e., I believe 

 that the two extremes and generally better-known forms are 

 connected by other intermediate forms. I hardly know whether 

 polymorphic is at all a correct word to use in this case, as there 

 are decidedly only two forms joined by intermediates." Of the 

 British species of Tortrix, Mr. Tutt tells me that xylosteana and 

 r'lbeana are polymorphic ; rosana, heparana, costana, and palleana 

 are dimorphic ; lafauryana, unifasciana, vihurnana, and palleana 

 var. icterana are sexually dimorphic ; ministrana has a melanic 

 form of restricted occurrence ; but the black form of podana is 

 not restricted to any particular district, being taken in Notts, 

 Yorks, Kent, Surrey, &c. In Penthma, says Mr. Tutt, " there is 

 a strange case of dimorphism, certain forms losing their dark 

 colours, and becoming white, with grey shades." Mr. Tutt has 

 such a form of P. variegana. In the birds of the genus 

 Nyctidromus, red and grey phases occur, the red being more 

 prevalent in the tropics (see Gr. B. Sennett, ' The Auk,' 1888). 



(f.) 1. Mr. W. H. Edwards, in Canad. Ent., 1876, 203, writes 

 that Lyccena corny ntas is " dimorphic in the female, most of this 

 sex here (Coalburgh) being black, the others blue, with broad 

 black margins. This phenomenon is similar to that of pseudargiolus 

 in its winter form violacea." But the black pseudargiolus have 

 since been found to be males, so perhaps the dimorphism of 

 comyntas is also really in the male. I incline to consider that 

 Lyccena presents an exception to the general rule, that in cases 

 of sexual dimorphism in Lepidoptera it is the female that has 

 varied from the original type ; and this is why we find that 

 almost unique phenomenon, a phase of dimorphism confined to the 

 male. 2. To the cases of pale female Coliades, C christ'ma $ pallida 

 (H.H.Lyman, Can. Ent., 1884, 6) and C. alexandr a ^ pallida 

 (W. H. Edwards, Can. Ent., 1887, 229) may be added. The 



