24 PROCEEDINGS OF THE NATIONAL MUSEUM vol. xxvii. 



ing to the genus Prohopyrus Giard and Bonnier. The list of 

 fresh-water Sphan-omida? is large for a marine family, and includes 

 the following forms belonging to the genera Sphxroma Latreille, 

 Ose-cosphseroma Dollfus, and Sphasromddes Dollfus: Sjphsermia dugesi 

 Dollfus from a warm spring in New Mexico; 8. thermophilum Rich- 

 ardson from a warm spring in New Mexico; S. destructor Richardson 

 from St. Johns River, Palatka, Florida; S. fossarum Von Martens 

 from a swamp; S. rugicauda Leach from brackish waters in Europe; 

 SphmromideH ray mond I DoWf us from subterranean waters; Cxcosjj/ias- 

 roma virei Dollfus and C. hurgundwn Dollfus from waters in grottos 

 of the Jura; C. faucheri DoWtws from subterranean waters near the 

 village of Sauve; and MonoUstris cseca Gerstsecker. 



With these exceptions all the forms belonging to the Chelifera, the 

 Flabellifera, the Valvifera, the Asellota, and the Epicaridea are 

 marine. 



The Ligiidsfi, a family of terrestrial Isopoda, are littoral forms, and 

 are found around wharf piles and under rocks and stones along the 

 shore. Prof. A. E. Verrill sa3^s of Lkjia haudiniana Milne Edwards: 



At the Bermudas the Ligia occurs in great abundance on the ledges and cUffs along 

 all the shores. It runs with surprising activity and quickly seeks refuge in the 

 cracks and crevices of the ledges, so that it is not easy to capture without injury. 



7. FOOD. 



Mollusks, Annelids, Crustacea, and fish seem to be the chief food of 

 the marine Isopods. The species Cirolana concharum (Stimpson) is 

 known to feed on the blue crab. From a single crab as many as 108 

 specimens of this form have been taken. It is recorded that the dog- 

 fish Sgualus acanthias has been reduced to a skeleton by Conilera 

 cylindracea (Montagu). The Isopods feed not only on the dead 

 animal, but the living animal is also their prey. 



It is supposed that the food of the fresh-water Isopods consists 

 mainly of Infusoria. 



The stomachs of certain of the land Isopods have, on examination, 

 been found to contain moss cells, algse, etc., so that a vegetable diet is 

 in some cases substituted for an animal diet. The Serolidfe are 

 strongly suspected of cannibalism (Stebbing). 



8. HABITS. 



Very little is known about the habits of the Isopoda, except as they 

 are destructive. It is a well-known fact that the Isopod, Limnoria 

 lignorum (Rathkc) commonly called the "gribble," attacks wood by 

 boring small holes, causing much damage to bridges, piers, etc. It 

 has also been seen attacking the gutta-percha of submarine telegraph 

 cables. 



There are two species of the genus Sphseroma which have this same 



