NO. 1350. NATURAL HISTORY OF THE ISOPODA— RICHARDSON. 



67 



are distinct. The terminal segment is broad, more or less bilobed. 

 The pleopoda consist of five pairs of double-branched lamellar append- 

 ages, closely crowded together on the ventral side of the abdomen. 



The five pairs of incubatory lamellae surround a large open area nor- 

 mally filled with eggs. The first pair have the terminal lobe of the 

 distal segment, large, well defined, and incurved. 



All the legs have a high quadrangularly shaped expansion or carina 

 on the basis. 



Male with all the segments of the thorax distinct, and with the lat- 

 eral margins contiguous. First four segments of the abdomen well 

 defined at the sides, but fused in the middle of the dorsal surface. The 

 last two segments form a single large piece, the fused terminal segment 

 being indicated only by a small median point on the posterior margin. 

 The body is a little more than twice as long as wide. Eyes are present. 

 The rudimentary pleopoda are pairs of small oval processes one pair 

 on each abdominal segment. The abdomen is about one and a half 

 times as broad as long. 



PROBOPYRUS ALPHEI (Richardson). 



Bopyrus sp. ? Fritz Muller, Jenaische Zeitschrift, VI, 1871, p. 68. 

 i?o;>;/nt.s oZpZiei EicHARDSoN, Proc. Wash. Acad. Sci., II, 1900, pp. 158-159. 

 Gyije sp. ? H. V. Wilson, American Naturalist, XXXIV, 1900, p. 353. 

 Bopyrus alphei Richardson, Proc. U. S. Nat. Museum, XXIII, 1901, p. 578. 



Locality. — Beaufort, North Carolina, on Alpheus heterochcBlis ; man- 

 groves, Rio Parahyba do Norte, Brazil, on A/j)heus heterochodis. 



As previously said,*^* this species is probabh^ 

 identical with the Bopyrus mentioned by 



Fritz Midler as being found 



on a species of Alpheun o\\ the 



coast of Brazil. Giard and 



Bonnier have referred their 



species Grapsicepon fritsU 



from the branchial cavity of a 



Gmj.)sus {Lej)foc/rapsus rugu- 



losus) to Fritz Midler's jBopy- 



7't(s recorded from a species of 



AJjy/ien.s. A difference, not 



only in the species, but even in the genus of host, 



makes this conclusion rather inconsistent with a certain 



hypothesis which these authors maintain, namely, that 



one and the same species of parasite can not infest dif- 

 erent species of Crustacea. The genus Grapsicepon Giard and Bonnier 

 is characterized by the fact that there are four pairs of triramous 

 a])pendages elongated and fi-inged to the first four segments of the 

 abdomen, those of the fifth segment being biramous. It does not seem 



Fig. 45.— I'ROBOPYRUS ALPHEI 

 DORSAL VIEW OF FEMALE. 



Fig. 44.— rRoBoPY 



RUS ALPHEI, MALE 



«Proc. Wash. Acad. Sci., II, 1900, p. 158. 



