Dr. Leacn’s Arrangement of the Crustacea, $c. 369 
Spec. 2. Spheroma rugicauda. 
S. corpore levi inermi, caudá rugulosà: lateribus oblique trunca- 
tis, lamellis ellipticis; externis margine externo vix denticulatis. 
Spheroma rugicauda. Leach, Edin. Encycl. vii. 405-433. 
Habitat in oceano Atlantico. 
Mus. Leach. 
Statura et magnitudo pracedentis, et satis distincta, caudá 
rugosá, lamellis rotundatis nec acutis, antennarum inferiorum pe- 
dunculo longè minus crasso. Color cinereus, nigro lineatus, ma- 
culatusque. Oculi nigri. | 
I discovered this species on the Isle of Ulva, one of the West- 
ern Isles,*over against Mull, in the month of August. It was 
much more agile than S. serrata, which called my attention to 
minute examination. I met with several, but owing to an ac- 
cident only one remains. 
Spec. 3. Spheroma Hookeri. 
S. corpore levi, caudæ articulo ultimo tuberculis duobus ob- 
longatis subobscuris. : . 
Spharoma Hookeri. Leach, Edin. Encycl. vii. 433. 
Habitat in Suffolcià ad littora maris; color cinereus aut rufescens, 
punctulis nigris sparsus. Cum copia crustaceorum benignis- 
sime communicavit amicus W. J. Hooker, cujus nomen gerit. 
** Antenne superiores pedunculo amplissimo. Ungues simplices. 
Gen. 26. Aiea. 
Oculi magni, granulati, oblongi, obliqui, marginales. Corpus T- 
articulatum. Cauda 6-articulata, articulo ultimo majore, basi 
utrinque appendicibus duabus foliaceis instructa. 
: ' Spec. 1. 
