146 BRITISH FOSSIL CRUSTACEA. 



written on the genus." 1 Mr. Banks figures (on plate ii, fig. 4, vol. xii, op. cit.) the 

 small, half-oval carapace, with somewhat remote eyes, as well as a few front body-segments. 

 Mr. Salter (' Quart. Journ. Geol. Soc.,' vol. xv, p. 232, pi. x, figs. 4 — 8) figures the entire 

 body and caudal joint with the sculpture of the head and body-rings, and he also indicates 

 the form of the small broad swimming-foot (reproduced on our PI. XXVIII, figs. 5, 6, 7). 

 " The body," writes Mr. Salter, " tapers rapidly backwards ; it is not four times the 

 length of the head, and is broadest at about the fourth segment. The first segment is 

 very narrow, not above half the width of the second ; and the rest are all transversely 

 broad until the eighth, when they begin to lengthen out, the [twelfth] 2 being square. 

 The telson is regularly long-triangular, the length being scarcely more than twice the 

 breadth. It is slightly keeled above ; the sides are straight ; the apex is not produced. 



" The elongation of the last body-joints before the tail helps to distinguish this small 

 species from a closely allied form in the shales of Lesmahagow, Lanarkshire. This has the 

 tail of the same shape, but a shorter head ; and the penultimate body-joints are nearly 

 one and a half times as wide as long. In other respects it is very similar. It is described 

 below as E. charlarius? 



" Of the swimming-foot we have the two expanded terminal joints ; taken together, 

 they are as long as the head, and form an oblong oval, the deep notch in the penultimate 

 joint being filled exactly by the oval terminal palette. The lobes on either side of this 

 notch are very unequal, the posterior being much the larger and longer." 



Locality. — Downton Sandstone (Uppermost Ludlow Rock) of Kington, Mr. R. 

 Banks's Collection. Upper Ludlow Shales, Ludford Lane, Ludlow, beds of passage at 

 the base of the Old Red Sandstone, in the railway-cutting, Ludlow (Messrs. Lightbody 

 and Marston's Cabinets). 



Species 4.— EURYPTERUS ACUMINATUS :— Salter. PI. XXVIII, figs. 13 and 15. 



Eurypterus acuminatus, Salter. Quart. Journ. Geol. Soc, 1859, vol. xv, p. 233, pi. x, 



figs. 17 and 19 (?). 



" We have," writes Mr. Salter of this species, " the tail-joints only. They are much 

 broader at the base than in Eurypterus [now Stylonurus] meyalops ; 4 but possibly they 



1 R. W. Banks, ' Quart. Journ. Geol. Soc.,' 1855 p. 99. 



2 The last segment before the telson is always spoken of by Mr. Salter as the eleventh ; for at the time 

 when his Memoir was published, 1859, he was unaware of the existence of twelve body segments between 

 the head and the telson. See Introduction, Part I, of this Monograph. 



3 Mr. Salter subsequently concluded that E. chartarius was only the young of E. lanceolatus (see p. 140). 



4 There appears no reason (save their accidental association together in the same bed) for attributing 

 the series of detached body-rings (referred to here by Mr. Salter, and reproduced on our PI. XXVIII, fig. 8) 

 to the head-shield of S. megaloj)s, which there is good reason to believe, by comparison with the other 

 species, had a more styliform telson than fig. 8 exhibits. 



