Dr. H. Woodward—On a Fossil Schizopod Crustacean. 405 
the marsupium are so imbricated that the last of the five pairs is 
outermost (op. cit., p. 394). In the Seroliide the marsupium consists 
of four pairs of sighs (op. cit., p. 857) [formed probably between and 
set free by the separation of the ventral cuticle from the hypodermis ]. 
In the Asellide the marsupial pouch is formed of plates pertaining 
to the first four, or to the second, third, and fourth segments of the 
thorax (op. cit., p. 376). 
In the Dajide the first four pairs of imbricated plates form a 
movable lid to the front opening of the marsupium, the large fifth pair 
close it behind (op. cit., p. 398). 
In the Entoniscide the marsupium is formed of five pairs of plates 
(op. cit., p. 405). 
In one of the forms of parasitic Isopoda, of the family Bopyridz 
(Lone thoracica), the imbricated plates of the brood-pouch in the 
female consist of seven pairs, and they closely resemble in form those 
of Pygocephalus, but they overlap one another in exactly the reverse 
order from back to front.’ 
There are other characters in the recent Peracarida which distinguish 
them from the Eucarida, in the structure of the mandibles and in 
certain characters presented by the thoracic limbs, but these we need 
not discuss here, as the fossil forms are not sufficiently delicately 
preserved, and cannot, of course, be dissected like recent specimens. 
Son 
Fic. 1 MS farephant Cooperi? (Huxley); from Coal-measures, Sparth, near 
Rochdale. Presented by Mr. Walter Baldwin to the British Museum (Natural 
History). Length of antenne, 50mm.; length of thorax, 25mm. ; length of 
hr 
abdomen, 25mm, a’. antennules : Cie antennee ; ec, ¢. lateral ‘border otf 
carapace; ab. abdomen; wr. uropods ; ¢. telson. 
In addition to the two well-preserved examples of the female in 
Mr. Herbert W. Hughes’ collection figured on our Plate (Figs. 5 
and 6), I have detected two imperfectly preserved females in the 
Museum collection (I. 1586), part of the late Mr.. Henry Johnson’s 
collection which I had previously overlooked. They serve to confirm 
the evidence afforded by Mr. Hughes’ more perfect specimens. 
1 Spence Bate & I. O. Westwood, ‘‘ Sessile-eyed Crustacea,’’ 1868, vol. 1i, p. 255. 
