434 Dr. H. Woodward—On the genus E’ryon. 
In 1883 M. Moriére described a second species of Hryon under 
the name of H. calvadosi' from the Upper Lias of Calvados. 
In 1884 Mr. C. Spence-Bate, F.K.S., figured and described a 
species of Eryon from the Lias of Lyme-Regis, Dorset, under the 
name of Archeastacus Willemesii.2 I ventured to point out, in 
a footnote to his paper (see Grou. Mac. 1884, p. 810) that the 
specimen so described was almost certainly identical with Hryon 
crassichelis, H. Woodw., 1866 (see Quart. Journ. Geol. Soc. 1866, 
vol. xxii. p. 497, pl. xxv. fig. 2). 
In August, 1888, the two fine volumes xxiv. (text and plates) of 
the “Challenger” Report on the Crustacea-Macroura by Mr. C. Spence- 
Bate, F.R.S., were received by me. In this magnificent Monograph 
the author discusses, under “ Morphology,” p. xv, and again under 
the Eryonide (pp. 100-120), both the past and present representa- 
tives of this family, and he gives a conjectural restoration of his 
“ Archeastacus Willemesii”’ (2? = Eryon crassichelis, H. Woodw.), 
which, however, differs considerably from the actual specimen, as may 
be seen by a comparison of the carefully-drawn Plate X. Grou, 1884, 
Mag. with the “Challenger”? woodcut on p. 117. 
The most important points to be noticed in the new figure are, the 
omission of the articulation (digresis) in the outer lamella (exopodite) 
of the sixth segment of the abdomen (forming the “rhipidura,” or 
“tail-fan” of Spence-Bate) ; the exaggerated size of the scaphocerite 
or antennal scale—certainly more than twice the natural size; and the 
incorrect representation of the basal joints of the antenna. This 
latter is due to Mr. Spence-Bate having mistaken the three terminal 
joints of the exopodite of the maxillipede (preserved in the fossil 
on the right side) for the basal joints of the antenna. The antennules 
in the original specimen do not bend outwards over the antenna as 
here represented, the former with their short bifid multiarticulate 
flagella being directed forwards, and the latter with its single 
flagellum, and short ovoid basal scale, being curved outwards. Lastly, 
it is quite certain that the latero-anterior margin of the carapace is 
not perfect in the fossil, and does not justify the representation given 
of a smooth rounded margin; the evidence on the surface of the 
carapace of a cervical furrow bifurcating on each side justifies the 
assumption that the margin would be intersected by two indentations 
one at the end of each branch of the cervical furrow, and marked by 
a more or less pointed lobe enclosed between these two indentations, 
a form of carapace most characteristic of the genus Hyon. 
In 1835 Mr. W. J. Broderip described in the Transactions of the 
Geological Society of London (2nd series, vol. v. pl. 12, figs. 1, 2, 
p: 172), a new Macrourous Decapod Crustacean from the Lias of 
Lyme-Regis, which he named Coleia antiqua. The larger fossil 
figured by Broderip is very imperfect, but the smaller is more com- 
plete; both examples display sufficient evidence in the carapace 
and appendages to have justified: Dr. Oppel in his conclusion that 
they belonged to the genus Hryon (Pal. Mittheil. 1862, p. 11). 
1 Bull. Soc. Linn. de Normandie, 1883, sér. 3, tome vii. pp. 1-10, pl. i.-1i. 
2 Grou. Mac. 1884, Dec. III. Vol. I. Pl. X. p. 307. 
