A Singular Parasitic hopod Crustacean and [January, 



THE material for the present paper 2 was obtained from the 

 common prawn of our shores, 3 Palczwonetes vulgaris Stimp- 

 son, 4 about ten per cent, of which I found infested, in June, 1881, 

 with a Bopyrus ( Bopyrus palcsinonelicola Packard 5 ), probably the 

 same species which Professor Joseph Leidy mentioned as occur- 

 ring near Atlantic city, N. J. 6 The female of our Bopyrus 

 averages in size from 3.50 to 4.50 mm in length, and 3 to 4 mm in 

 width. Its ventral side is invariably turned toward the carapace of 

 the prawn and its marsupium or breeding cavity is usually filled 



with minute yellowish eggs of a nearly spherical form. From 

 three hundred to three hundred and fifty eggs are contained in 

 this cavity; the latter being formed by the prolonged lamellate 

 margins of the thoracic segments. 



The body of the female is of a whitish color, and as in all 



xS^^fFJ 



eiNihnft fii 



r Median i 

 (B.»|.ynis an 



md Naturw 



,1 Cryptoni- 



--I 





ten, Vol. 



» Read before 































• note in Sci 













'Annals Lye 



eum Nat. H 





, Vol. x, p. 





871. 





5 Zoology foi 



• High Sch> 



doIs and Co 



lieges. By 



A. S. 



Packard, Jr. 



1881,3d ed. 















6 Proceedings 



Academy of Nat. Sciei 



ices, 1879. 



See 



also 



Report 



Isopoda of Net 



,v England. 



By Professor Oscar Hi 



lifer. 



P- 



312. 



