On Blind Fish, Cray-fish, and Insects from, the Mammoth Cave. Ill 



the epimera, and the structure of the terminal buckler of the 

 body ; but it is essentially distinguished from Serolis by the con- 

 siderable development and evident mobility of the first rings of 

 the abdomen, a character which connects it with the j^ffce and 

 other erratic Cymothoida. The several segments comprised be- 

 tween the head and the caudal buckler scarcely differ among 

 themselves, so that there is no visible limit between the thorax 

 and the abdomen ; but they are twelve in number, and as the 

 thoracic segments never exceed seven throughout the division of 

 Edriophthalmia, we must conclude that the five hindmost ones 

 belong to the abdominal portion of the body, which would conse- 

 quently consist of six moveable segments, as in the genera ^ga, 

 Nelocira, &c. The sixth segment of the abdomen, which composes 

 the terminal buckler already mentioned, is almost semicircular, 

 and exhibits in its medial and anterior portion a tubercular swell- 

 ing somewhat analogous to that observed in the same part in 

 various Spharomatidce. It appears to me also that the margin 

 of this piece is notched laterally to give insertion to an appen- 

 dical portion placed in the same manner as in Serolis. We may 

 also infer, from the arrangement of the lateral pieces of the other 

 abdominal and thoracic segments, that the animal possessed the 

 power of rolling itself into a ball like the Spha7'omatid(E. Lastly, 

 the structure of the head appears intermediate between that of 

 the last-mentioned Crustaceans and that which is exempHfied 

 in Serolis, for the cephalic segment is widened like that of Se- 

 rolis. 



From the facts thus indicated it appears that this fossil Crus- 

 tacean is probably distinct from all Isopods hitherto known, and 

 ought to be classed in a separate generic division. I propose 

 then to designate it by the name of Archceoniscus Brodii. 



[The memoir then proceeds to describe a second species of 

 fossil Isopod, found in the neighbourhood of Paris, and denomi- 

 nated by the author Palceoniscus Brongniartii.~\ 



XVII. — Notice of the Blind Fish, Cray-fish, and Insects from the 

 Mammoth Cave, Kentucky^. 



At a meeting of the Belfast Natural History and Philosophical 

 Society, January 17, 1844, Mr. Thompson, the President, called 

 attention to specimens of the Blind Fish, Cray-fish, and Locusts 

 from the great Mammoth Cave in Kentucky, procured in the 

 month of May last specially for the Society by the kind attention 

 of our to\NTisman Gordon A.. Thomson, Esq. on his visit to the 

 cave. They are perhaps the first examples of their respective spe- 

 cies brought thence to Europe. 



* Communicated by Mr. Tliompson. 



