214 Miscellaneous, 



The animals associated with the Megalonyx are, an Ursus, a Bos, 

 two species of Cervus, one or two species of Equus, and several un- 

 determined genera, all which are now in progress of delineation and 

 description for the Academy's Journal. 



Dr. Dickeson presented another relic of yet greater interest, viz. 

 the fossil OS innominatum of the human subject taken from the above- 

 mentioned stratum of blue clay, and about two feet below the skele- 

 tons of the Megalonyx and other extinct genera of quadrupeds. 



This ancient relic of our species is that of a young man of about 

 sixteen years of age, as determined by its size and form, and by the 

 fact that the epiphyses have separated from the tuberosity of the 

 ischium and from the crista of the ilium. Nearly all the os pubis is 

 wanting, the upper posterior part of the ilium is broken away, and 

 but half the acetabulum remains. That this bone is strictly in the 

 fossil state is manifest from its physical characters, in which it ac- 

 cords in every respect of colour, density, &c. &c. with those of the 

 Megalonyx and other associated bones. That it could not have 

 drifted into the position in which it was found is manifest from 

 several facts: — 1. that the plateau of blue clay is not appreciably 

 acted on by those causes that produce ravines in the superincumbent 

 diluvial ; 2. that the human bone was found at least two feet below 

 three associated skeletons of the Megalonyx, all which, judging from 

 the apposition or proximity of their several parts, had been quietly 

 deposited in this locality, independently of any active current or other 

 displacing power; and lastly, because there was no admixture of 

 diluvial drift with the blue clay, which latter retains its homogeneous 

 character equally in the higher part that furnished the extinct quad- 

 rupeds, and in its lower part that contained the remains of man. 

 Dr. Dickeson has announced his intention of returning, at an early 

 period of the present autumn, to resume his explorations in this pro- 

 lific and most interesting locality ; and it is earnestly hoped that his 

 researches may lead to a further elucidation of this important ques- 

 tion in science. 



On the Mechanism which closes the Membranous Wings of the genus 

 Locusta. By Joseph Leidy, M.D. 

 The membranous wings or alse of the locusts while at rest are 

 folded up, like a closed fan, beneath the anterior pergamentaceous 

 wings. These are opened or expanded by the contraction of appro- 

 priate muscles (extensores alee) contained within the thorax, the 

 tendons of which are inserted into the ribs or longitudinal veins at 

 the root of the wings. When one of the wings is separated from 

 the body of the insect and stretched open by the fingers, upon let- 

 ting go it will be found instantly to close or resume the position of 

 rest. 



The mechanism which produces this closure in the separated wing, 

 as well as when attached to the living animal, I find to be spiral 

 ligamentous bands, wound, like the thread of a screw, around the 

 transverse or connecting veins, which latter are also flexible. By 

 this arrangement, upon the contraction of the alary extensors, the 



