42 ME. J. CARTER ON THE PALEONTOLOGY OF [Feb. iSpSy 



Distribution. — London Clay. Specimens are in the Woodwardian 

 and Jermyn Street Museums. Examples (derivative) from the Red. 

 Crag are in the Woodwardian Museum, etc. 



Genus Podopilttmnijs, M'Coy. 



PODOPTLUMNTJS FlTTONI, M'Coy. (PI. II, fig. 7.) 



1849. M'Coy, Ann. & Mag. Nat. Hist, ser, 2, vol. iv, p. 166. 

 1854. M'Coy, ' Contrib. Paljeont.' p. 121. 

 1854. Morris, ' Cat. Brit. Foss,' 2nd ed. p. 114. 



1859. Reuss, ' Zur Kentniss foss. Krabben,' Denkschr. k. Akad. Wissensch. Wien,- 

 vol. xvii, pp. 8, 79. 



1865. Milne-Edwards, Ann. Sci. Nat. ser. 5, vol. iii, p. 315 & pi. vi, fig. 6. 



Description. — Carapace about a third wider than long; slightly 

 convex transversely, cephalic portion strongly deflexed in front. 

 Orbito-frontal border nearly straight ; width rather less than half 

 that of the carapace ; interorbital portion occupied by a broad,, 

 flattened, quadridentate rostrum. Orbits transversely oval, margins 

 irregular. Antero-lateral border moderately arcuate, slightly keeled^ 

 and bearing three small, distant, pointed processes. The postero- 

 lateral margin is longer than the antero-lateral and undulates 

 inward, making the width of the posterior margin about equal 

 to that of the orbito-frontal. The normal dorsal regions are 

 indistinctly defined. A shallow median sulcus extends from the 

 rostrum. The whole surface of the carapace is nearly smooth, but 

 under the lens small granulations of various sizes are visible, espe- 

 cially near the borders. The inferior branchiostegite is sparsely 

 granular, and bears a sharp, curved, granulated ridge. Sternal 

 plastron broadly ovate, half as wide as the carapace. Pemale 

 abdomen broadly ovate, segments apparently distinct ; the five 

 anterior are of equal length and much wider than long. Chelae 

 robust ; meropodite considerably shorter than the propodite ; carpo- 

 podite large, rhomboid, granulated ; hand rather longer than wide ; 

 the dorsal surface is singularly sculptured by minute Cypris-Wke 

 markings, and bears several rows of small tubercles extending from 

 the carpal articulation towards the fixed finger ; anterior border 

 tuberculated ; fixed finger shorter than the hand, and calcareous,, 

 the inner border being coarsely dentated. The four posterior pairs 

 of limbs are large and long : the meropodite of the fourth pair 

 measuring half the width of the carapace. 



Length of carapace = 06 mm. ; width =48 mm. 



Affinities. — This genus is clearly referable to the Portunidse. 

 Milne-Edwards has fully discussed the alliance of this form, and 

 regards its relationship vnth Pilumnus as remote. 



Distribution^ etc. — The only known specimen of this species is 

 that in the Woodwardian Museum described by Sir Prederick 

 M'Coy. It is labelled ' Greensand, Lyme Regis,' but there is doubt 

 both as to the rock and the locality from which it came. Sir 

 Richard Owen ^ regarded it as ' probably from some Tertiary 

 deposit.' It is quoted and figured as a British fossil by Milne- 

 Edwards, Bronn & Roemer, and Pictet. The figures given by these 

 ^ ' Palaeontology,' Edinburgh, 1860, p. 46. 



