Dr. H. Woodward—On a Fossil Schizopod Crustacean. 407 
broad uropods. Further research may show that the adult female 
differs from the male not only in the possession of marsupial plates, 
but in the form of its caudal plates also. 
Another specimen from Sparth, Rochdale, was referred to by me 
a year ago (Brit. Assoc. Reports York Meeting) under the manuscript 
name of Anthrapalemon Parkeri, H. W., but examining this specimen 
more critically I think this Crustacean should be referred to 
Pygocephalus, not to Anthrapalemon. If this view is correct it is 
the only example hitherto met with in which the entire dorsal aspect 
of the Crustacean lies exposed. 
It differs from Pygocephalus Coopert in having four small and one 
large serration on the latero-anterior angles of the carapace, but the 
telson and its uropodites agree exactly with Pygocephalus. The 
antenne also bear a large oval scale as in Pygocephalus. Although 
my evidence is incomplete I venture to place this form in the genus 
Pygocephalus, with the trivial name of Parkeri, after its discoverer, 
Mr. Wm. Albert Parker, F.G.S., of Rochdale. 
In conclusion, I wish to thank my friend Dr. Calman for the very 
kind advice and assistance which he has given me in this investigation, 
and for the trouble he took in examining the specimens showing 
marsupial plates in order to verify my interpretation of their true 
nature. 
EXPLANATION OF PLATE XVIII. 
PycocerHaLus CoorErt, Huxley. 
Coal-measures—Clay Ironstone: Coseley, near Dudley. 
Fic. 1.—View of ventral aspect of male specimen, ¢. 
a.s. antennal scale; @’. antenna; a’. antennule. 
¢. margin of carapace. 
th. hexagonal thoracic plates (sternites). 
per. series of thoracic limbs (pereiopods). 
ab. abdomen flexed ventrally upon the thorax. 
2.—A single thoracic appendage (after Huxley) showing (en.) the endopodite 
and (ev.) the exopodite. 
», 3.—Part of another specimen of male Pygocephalus, g. 
th. thoracic sternites somewhat displaced. 
per. five of the thoracic limbs showing endopodite and exopodite. 
a.p. doubtful (anal ?) plate displaced. 
», 4.—An attempted restoration of the male g underside, showing the antennules 
(av, @.); the antenne (a”, a’.) with their long flagella and broad antennal 
scale (a.s.); the 7 thoracic sternites (¢f.) with corresponding paired 
pefelopods, each with exopodite and endopodite, the 5 abdominal plates 
(a.b.), followed by the telson (¢.) with its two paired uropodites (w7.). 
Figs. 5 and 6.—Females of Pygocephalus Cooperr, showing 6 or 7 broad, scale-like, 
imbricated plates (m.p.), ‘ oostegites,’ forming the marsupium in which 
the eggs and the immature young are carried. The other parts lettered 
are the same as in the male examples (Figs. 1, 3, 4). 
Fie. 7.—Carapace with cephalo-thoracic appendages and marsupium (m.p.) of recent 
female Schizopod (Zucopia australis, Dana), copied from Challenger 
Report (Zoology), vol. xiii (Schizopoda), pl. 1x, fig. 2. Enlarged about 
13 times nat. size. 
8.—Antennal scale (a.s.) with part of flagellum and basal joints of antenna of 
Eucopea (from same plate as Fig. 7). 
9.—One ot the legs of Ceratolepis showing endopodite and exopodite, copied 
from same volume of Challenger Report as Figs. 7 and 8 (op. cit., pl. 1, 
fig, 14). 
9 
2? 
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