122 Zoological Society. 



feet at Lecropt Church, about 900 feet at Airthrey Mineral Well, and 

 nearly half a mile at Airthrey Castle. Several openings have been 

 cut in it b)"^ streams or other agents. The preservation of this por- 

 tion of the ancient sea-bottom may be attributed to the high trap 

 hill of Abbey Crag at its east end, which had protected it from the 

 action of the tide v/hen the sea covered the Carse. A remnant of 

 another terrace at a corresponding level is found at the opposite side 

 of the Carse, two miles southward, near Whitehouse Farm, and small 

 portions of a terrace fifty feet lower are found at Stirling Castle and 

 near Causeyhead. 



January 6, 1845. — 1. " Further Remarks on the Electrical Organs 

 of the Rays." By Dr. Stark. 



2. " Observations on the same subject." By John Goodsir, Esq. 



Mr. Goodsir stated that he had examined the part described by 

 Dr. Stark, It was, as he had suspected, the posterior part of the 

 middle mass of the caudal mu&cles. The texture of this part differs 

 remarkably from the muscular ; it consists of numerous compart- 

 ments formed by the aponeurotic septa of the muscle. Each com- 

 partment contains next its walls a rich festooned arrangement of 

 nervous loops, these loops being generally united three by three ; 

 the sling of each loop is enlarged and contains one or more nu- 

 cleated corpuscules, the limbs passing back into nervous tubes of 

 the usual size. With these nervous loops, blood-vessel loops simi- 

 larly enlarged are intermixed. The centre of each compartment con- 

 tains a gelatinous mass applied externally to the nervous loops, and 

 in its interior containing a vacant space. The gelatinous mass con- 

 sists of areolae formed by bars passing in all directions : these bars 

 are thickest where they meet one another : they consist of a series 

 of nucleated cells, which are plump and gelatinous in appearance, 

 and much larger at the points of junction of the bars. These larger 

 cells Mr. Goodsir considers as the germinal spots of the texture. The 

 bars, and consequently the whole arrangement of the gelatinous 

 mass, appear to be covered by a membrane presenting a most re- 

 markable appearance, — a series of grooves or lines, the general di- 

 rection of which is parallel to the bars, but generally slightly in- 

 clined. These grooves resemble the grooves or lines of mother- 

 of-pearl, or the groovings on the dermal plates of some of the older 

 fossil fishes. 



Mr. Goodsir concluded by stating that this organ had the general 

 appearance of an electrical organ, but that the evidence educed of its 

 electrical properties appeared to him to be insufficient. 



ZOOLOGK'AL SOCIETY. 



June 11, 1844. — George Gulliver, Esq., in the Chair. 



" On the Blood-corpuscles of the Two-toed Sloth, Brady pus didac- 

 tj/Ius, Linn.," by George Gulliver, F.R.S. 



From an observation which I have lately made, it results that the 

 Two-toed Sloth is one of the very few animals that has blood-discs 



