M A R I U S (Petreus) Thetys, 

 Thetys Butterfly. 



Family Nymphalidae. Sub-family Paphianse. Genus Marius. 

 Sub-genus Petreus. (Heliconian Type.) 



Sub-Generic Character. 



Superior wings long, horizontally lengthened ; Larva naked, with 3, 

 4 fleshy filaments on the body. 



Specific Character. 

 See pi, 56. 



The perfect insect, or butterfly, of this elegant species, 

 we have already figured at pi. 59 of our second volume : and 

 that our illustration of a form so interesting may be com- 

 plete, we have now delineated the caterpillar and the 

 chrysalis, as given by Stoll ; together with a sprig of 

 the Cashew tree upon which it feeds. Every entomologist, 

 upon looking to the perfect insect, will immediately be 

 struck with its resemblance to the long-winged Heliconian 

 Butterflys, and to the genus Euploea, which is the Ery- 

 cipian type of that family. Now this resemblance, which 

 hardly requires pointing out, is a perfectly natural analogy ; 

 and is confirmed in the most remarkable manner by the 

 caterpillar, which puts on that peculiar form which dis- 

 tinguishes Euploea. The species in short, in every stage, 

 exemplifies the truth of that fundamental law of nature 

 which Ave have elsewhere so fully illustrated, viz. "that 

 " every natural group, contains representations of all others 

 "in the same class," following each other precisely in the 

 same series : thus establishing a truth which has long been 

 suspected, but not before demonstrated, that the laws of 

 variation are precisely the same in every group throughout 

 the animal kingdom. The genus itself represents the 

 Swallow-tailed types already figured (Podalirius, Pro- 

 tesilaus, and LeptocircusJ, but of the three remaining 

 sub-genera of Marius, we are as yet ignorant. It is, 

 however, by this genus that the two sub -families of Paphi- 

 anae and Heliconinx are united ; as it blends into the 

 latter by means of the genus Fabius, which we shall 

 shortly illustrate. 



