ACADEMY OF SCIENCES. 143 



the case. The edges of the pieces of wood are always neatly rounded by the 

 insect, and all outstanding branches are bitten off. Chrysalis, with the ab- 

 dominal portions, light chestnut brown, with the wing cases almost black. It 

 is nearly tubular in form, smooth, with some small hooks on the abdominal 

 segments. 



Length, 0.65 inch. 



Discovered by Prof. Geo. Davidson on Mt. Diablo, on the branches of 

 Gastaneopsis chrysopkgUa,, Dougl., (chinquapin chestnut) . I have much pleas- 

 ure in recording this interesting discovery by attaching to the species the 

 name of our respected President. 



It will be observed, both in the present species and one closely allied to it 

 from Australia, that there are, as I have shown, in most of the cases, some 

 pieces of twigs longer posteriorly than those of which the remainder of the 

 case is composed. It has struck me that these may be intended as a means 

 to assist the male insect, on arriving at the perfect state, to escape from the 

 body of the tube, the twig affording foothold and enabling the creature to 

 draw its somewhat unusually long abdomen from the aperture. I do not state 

 this as a fact, but the subject is worth the observation of those who may be 

 fortunate enough to have the opportunity. I suspect that the cases contain- 

 ing males only have these lengthened sticks, but if this be so we are utterly 

 at a loss to understand the process by which the creature arrives during the 

 caterpillar stage at a knowledge of its sex, and so frames its habitation accord- 

 ingly. 



Regular Meeting, December 1, 1876. 



President in the Chair. 



Donations to the Museum : From S. B. Christy specimen of 

 Molybdenum from Red Jacket Mine. 



Professor Davidson read a continuation of his papers on Ir- 

 rigation, describing the North Sea Canal of Holland. 



Pacific Coast Lepidoptera, No. 21. Descriptions of two 

 new species of the Genus Thecla. 



BY HENRY EDWAKDS. 



Thecla Pulnami. n. sp. Hy. Edw. 



9 . Upper side. Pale fawn color, shading into dark drab or stone color at 

 the base and costal margin. Fringes entirely white. Secondaries with a se- 

 ries of four indistinct lunulate spots, black, edged beneath with white; anal 



Paoc. Cal. Acad. Sci., Vol. VII.— 10. 



