8 A Singular Parasitic Isopod Crustacean and [January, 



me that, when black, the pigment is centrally located in the legs. 

 The thoracic segments have, as apparently in all Bopyridae, their 

 margins prolonged into more or less lanceolate pigmented lamel- 

 lae. To these lamellae the feet are attached. The lamellae attached 

 to the first pair of feet is a small, beautifully pigmented oval lobe, 

 and its entire margin is fringed with delicate tentacles. The sec- 

 ond and third pair of feet have very broad lamellae, with forward 

 directed sub-ovate tip, and with their anterior margins fringed. 

 The fourth, fifth and sixth pair of foot-lamellae are short, broad 

 and irregularly triangular pieces; seventh lamella very long, nar- 

 row, lanceolate. 



The marsupium is an open, roundish cavity, surrounded by the 

 above-mentioned lamellae, and covered by the carapace of the 



The abdomen is deeply segmented, and ventrally provided 

 with roundish appendages overlapping each other in the median 

 line. I have closely observed the live females, and doubt that 

 those abdominal appendages functionate as gills. They consist 

 of a larger thick fleshy lobe, and a smaller, still thicker roundish 

 piece. They are the degenerate postabdominal legs, characteris- 

 tic of the order of Isopoda. Usually four, but sometimes six 

 pairs of the thoracic epimera are more or less black pigmented. 



The male averages about i m,n in length by 0.25 mm in width. 

 Head with a pair of lateral pigment eyes. Head and seven 

 thoracic segments black pigmented, the pigment exhibiting, beside 

 the ordinary form, a pretty stellar arrangement. 



Anterior angles of thoracic segments oblique, abdominal seg- 

 ments four, pale, their margins perfectly round, segments gradu- 

 ally becoming narrower toward the terminal median piece, which 

 is minute, and, on treating with acetic acid, is seen to consist of 



The last of the thoracic segments, not being as fully pigmented 

 as all the preceding, exhibits dorsally a twisted, serpentiform 

 (bretzel- shaped) marginal ornamentation. 1 Eight pairs of legs 

 with powerful claws. Antennae apparently two-jointed, first joint 

 club-shaped, with five minute bacilli on its tip, second joint much 

 narrower, about one-quarter as long as the first, with six bacilli 

 at its tip. 



