SI 



D. 14; P. 13; A. 12; V. 11 ; C. 19, with 

 accessories. Length 5 inches. 



The three specimens from which this descrip- 

 tion was taken were obtained by Mr. Nevins 

 from the San Leaudro creek. They are evident- 

 ly young fish. 



Donations to the Library — American Philo- 

 sophical Transactions, Vol. X ; Notes on the 

 Classification of the Carabidae of the IT. States, 

 and Revisions of the Elateridae, by John Le 

 Conte, M. P., from the Author ; A Memoir of 

 Samud George Morton. M. D., by Charles Meigs, 

 M. D., from the Philadelphia Academy of Natu- 

 ral Sciences ; also a Notice of the Origin, Pro- 

 gress and Present Condition of the Academy, 

 with its Proceedings from Jan. 3d 1854 to Au- 

 gust 29th 1854. 



Catalogue of the described Coleoplera of the 

 United States, by Friedrich Ernst Melsheimer, 

 M. D., from the Author ; also Journal of the 

 Academy of Natural Sciences of Philadelphia, 

 Vol. VII, part II., Vol. VIII, part I. and II., 

 together with the first and second Volumes of 

 the new Series. 



Dr. Win. 0. Ay res presented a specimen, a ca- 

 nine foetus of full term, exhibiting a singular 

 instance of abnormal formation resulting from 

 the union of two ova, one developed of course in 



part at the expense of the other. 



Externally, the head, neck, left fore-leg, trunk, 

 and posterior extremities showed nothing worthy 

 of attention, except the entire occlusion of the 

 auditory opening on both sides. From the ab- 

 domen, however, anterior to the umbilicus, pro- 

 truded on a broad pedicel the hind legs which 

 belonged to the arrested ovum. They were placed 

 with their anterior surface toward the same sur- 

 face of the other pair, but were much smaller 

 and weaker. In the place of the right fore-leg 

 was a member consisting of three legs, joined in 

 one. the outer one evidently belonging to the 

 trunk to which it was attached, the other two 

 being the pair which corresponded to the super- 

 numerary posterior extremities. They were of 

 uniform size, the feet in a measure distinct from 

 each other. 



On removing the integuments, an ovoid body 

 half an inch in length was brought to view, lying 

 on the outside of the abdominal muscles. This 

 was a kidney, belonging to the protruding poste- 

 rior extremities, and connected with them in a 

 normal manner; but it was the only one with 

 whieli they were provided. 



The developement of these extremities was 

 found to be very imperfect. The pelvis consisted 

 of two slender, nearly cylindrical cartilages, pla- 



ced longitudinally side by side, united at their 

 anterior part, and ending there abruptly without 

 trace of vertebra?. The position of the muscles 

 was merely indicated, the chief part of the 

 bulk being made up of adipose tissue. The 

 circulation for these members was drawn from 

 the descending aorta, by a single branch of no 

 considerable size, just above the great mesenteric. 

 The only portion of alimentary canal which ap- 

 pertained properly to them was a rectum, which 

 branched from the main canal, and even for this 

 no outlet existed. 



The liver connected with this ovum was a mere 

 lobe projecting from the upper surface of the 

 normal one. 



The organs belonging to the most developed 

 of the two ova, (that which seemed to constitute 

 the true animal, of which the other was only an 

 appendage) were all of normal and healthy con- 

 dition. The arterial distribution from the heart 

 presented nothing peculiar. The subclavian go- 

 ing to supply the triple arm was not even chang- 

 ed ; after passing the axillary region it divided 

 into three branches and was thus enabled to reach 

 the whole space. (The three humeri were per- 

 fectly joined, forming one fiat bone, and articula- 

 ted with a single scapula ; in the fore-arm all the 

 bones were soldered, except the external radius.) 

 The nerves were merely those of a single arm 

 divided like the artery. 



The placenta of the one ovum was joined with 

 that of the other ; the vessels remaining separate, 

 though included in one cord, and each ramifying 

 on its own organ. 



March, 26, 1855. 

 Col. L. Ransom in the chair. 



Dr. T. L. Andrews presented a copy of Dana's 

 Mineralogy. 



Dr. Laub, U. S. A. presented a specimen of 

 silicified wood, found at Benicia in sandstone. 



Mr. S. V. Bowman presented two specimens 

 of a large and remarkable Crab, taken in the 

 vicinity of the Farallones. 



The thanks of the Academy were voted for 

 the donations. 



Dr. Kellogg exhibited a drawing and specimens 

 of a plant from Alameda known as the Califor- 

 nia Elecampane. 



The general appearance of this low, grey-leav- 

 ed Sun-flower, shooting up from the earth large 

 clusters of broad lance leaves from the branching 

 head roots and suckers around the flower stem, 

 very aptly suggests the common name. The 

 root is of a dark colored texture with radiating 



lines similar to the Elecampane. The odor is 

 strongly balsamic, or terebinuiine. 



