26 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



detected by the large swelling or protuberance at one side of the 

 body. A new genus of Bopyridie is descril)ed in the following pages, 

 which occupies a position in the visceral chamber of a species of 

 Munida, this position with reference to the host never having been 

 heretofore recorded of a parasite of this family. The Entoniscidse, 

 parasitic on the Brachyura, always occupy the visceral cavity of the 

 body of the host, entering through the branchial cavity. 



The DajidfB are found attached to Schizopoda, and usually occupy 

 a position on the back of the host, but they may also attach themselves 

 on the ventral side to the branchiffi of the gill chamber or to the 

 abdomen on the dorsal side. The Cryptoniscidse. are parasitic on 

 Amphipods, other Isopods, Ostracoda, Cirripedia (usually the para- 

 sitic Cirripedia known as the Rhizocephalia), and are sometimes found 

 in the incubatory pouch of deep-water Mysidoe. 



One host may carry as many as four parasites. Dr. Fraisse found 

 a Peltogaster^ a Cryptoniscus., an Athelges, and a Fseudioiie on one 

 Pagurid. One branchial and one abdominal parasite, or two branchial 

 parasites, one on either side of the body, is not uncommon. 



Other abiding places for shelter and protection are found l)y other 

 Isopods. The Anthurid Etstothistos vermiformis Haswell occupies 

 the tube of a Venn Ilia ^ and in the elongated shape of the body and 

 the smallness of the limbs resembles the original occupant. The 

 posterior part of the body, with its expanded appendages, serves well 

 to imitate the branchireof the head region of the Serpida, which issues 

 from the free end of the tube, the Anthurid entering the tube in the 

 reverse direction from its former occupant, with head foremost. 



y^ga spong'wphUa Semper lives in a silicious sponge. Species 

 belonging to the genus THanethes Schioedte are found in caverns; 

 species of Platyarthrus Brandt are myrmicophile forms, dwelling in 

 ants' nests, and Leptaspidm hrevipes Bate and Westwood was first found 

 in the iibrous nest of a mollusk. 



The species belonging to the genus Cleantis Dana are supposed to 

 be tube dwellers. 



Ichthyoxenus jellinghausii Herklots bores a hole in the body of the 

 fish, Puntiu.s maculatus Bleeker, just behind the fins, where it lives 

 with its mate (Stebbing). 



Many Isopods are confined to caves, and lead a subterranean life. 

 Ccecidotea stygius Packard was first found in Mammoth Cave; it has 

 been recorded from Wj^andotte Cave also (it is not confined to caves); 

 Ccecidotea richardsonoe Hay comes from Nickajack Cave, as well as 

 Ccecidotea nickajaclcensis Packai'd; JBrachenridgia cavernum Ulrich 

 comes from Ezell's cave and Beaver Cave near San Marcos, Texas; 

 species of the genus Ccecospho'roma Dollfus seem to be confined to 

 grottos, l)eing found in subterranean waters; Sp/i»romides raymondi^ 

 Dollfus comes from subterranean waters in a Cevennes grotto; Triclio- 



