Rafinesque on a fossil Medusa. 28? 



Description. — Length or height of the specimen six inch- 

 es, breadth above three inches. Back rounded convex 

 conical, nearly acute, dividing hself gradually underneath in 

 three branches or peduncles, all unequal in length and size, 

 the axilla or sinuses of the division are also unequal and ob- 

 tuse. The lateral peduncles are quite detached from the 

 middle one, and slightly curved outside : they are both situ- 

 ated obliquely, and slightly compressed in the direction of 

 the obliquity. The longest peduncle is also the slenderest 

 and quite obtuse at the end ; the shortest which is opposed 

 thereto is the thickest and shghtly obtuse at the end ; its 

 length is only about two and a half inches, while the long- 

 est is about four and a half inches long. The central pe- 

 duncle is quite straight, obliquely compressed also, attenua- 

 ted at the end and about four inches long, the opening is ter- 

 minal and furnished above on each side by a large fascicle of 

 tentacula, assuming a kind of fringed appearance ; they are 

 capillary, flexuose and thickly fasciculated, longer than the 

 central peduncle and reaching the end of the longest pedun- 

 cle, the outside tentacula appear to be the longest. The 

 longitudinal section of the animal shows an appearance of 

 internal vessels as in many medusas : three central faint ves- 

 sels appear to run through the peduncles in a shghtly flex- 

 uose form and to unite near the back, while the whole cir- 

 cumference shows many short capillary vessels deriving 

 from the surface, extending obhquely inside, but not reach- 

 ing quite to the central vessels. A transverse section shows 

 the curious respective obliquity of the peduncles, and that 

 their inward circumference is slightly striated by those small 

 superficial vessels. 



Specific observations. — This interesting animal remaii; 

 was found in 1817, by Mr. J. D. Chfford, near Lexington 

 in Kentucky, in an upper stratum of compact bluish lime- 

 stone, granulated and crystalhzed : the specimen is quite 

 imbedded in it, of the same appearance, but rather smooth- 

 er and of a paler colour. It was not accompanied by anj 

 shell nor other fossil, but stood alone, and rather below thc- 

 stratum where so many shells are found. I have dedicated 

 the species to its discoverer, in whose rich museum it is to 

 be seen. C. S. RAFINESQUE. 



Philadelphia^ 12th January y 1819, 



