1855.] 



SALTER — HIMANTOPTERUS. 



33 



we do not yet know the head of the latter, we must for the present 

 keep the species distinct ; and I propose to dedicate it to Mr. R. 

 Banks of Kington, who has lately been making discoveries amongst 

 the tile- stones, and has sent good specimens of this and other fossils 

 to London. 



Phyllopoda ? 



Among the Lanarkshire specimens, so well collected by Mr. Sli- 

 mon, are perfect forms of the genus Ceratiocaris, M'Coy*. Only 

 the carapace has hitherto been discovered ; but the occurrence of 

 body-rings in the Dudley limestone has been for some time known ; 

 and in the Ludlow Museum I lately saw such body-segments con- 

 nected with the long triple tail-spines now known under the name of 

 Leptochelesf. 



Fortunately these specimens from Lesmahago have all the parts 

 in juxtaposition, and show the animal to have been a large Apus-like 

 Crustacean, with a carapace bent sharply down the dorsal line, 

 pointed anteriorly and truncated behind, and with an elongate ab- 

 domen of at least five, if not six, joints, — the hinder ones longest. 

 The last joint is a thick striated spine, with a bulbous articulation, 

 and has a pair of lateral spines or appendages at its base, nearly as 

 long as itself. 



Fig. 8. — Diagram q/" Ceratiocaris, M'Coi/, with hody and tail-spines 

 attached ; from perfect specimens found in Lanarkshire. 



The resemblance to Hymenocaris, except in the presence of the 

 strong caudal spines, is sufficiently clear from the accompanying 

 woodcut (fig. 8). 



Now that we know the entire structure of this genus, it must be 

 removed from the Limnadiadce. 



It has a nearer resemblance to Apus and Dithyrocaris, but differs 

 at once from the latter genus by the deflected sides of the carapace, 

 and apparently too by the want of regularly-shaped smooth eyes, for 



* Synopsis Brit. Pal. Foss. Cambridge Mus. fasc. 1. p. 137. 



t M'Coy, Syu. Brit. Pal. Foss. Camb. Mus. fasc. 1. p. 175. 



VOL. XII. PART I. D 



