16 MR. J. CAETEfi ON THE PALEONTOLOGY OF [Feb. 1 898 



I. Macktiea. 

 Family Astacomorpha. 

 Genus Nepheops, Leach. 

 Nepheops Eeedi, sp. nov. (PI. I, fig. 1.) 



Description. — Chelae elongate; basal portion of propodite — ' hand ' 

 — more than twice as long as wide ; a double row of large bluntly- 

 conical tubercles, the apices of which are directed forward, runs 

 along both the outer and inner borders as far as the base of the 

 fingers. On the dorsal surface a series of 10 to 12 tubercles, larger 

 than those on the border, and placed upon a broad ridge, extends 

 from the carpal end to the base of the fixed finger ; the spaces 

 between the median and the marginal rows are slightly concave 

 and nearly smooth. The palmar surface also bears a median series 

 of large tubercles of unequal size, which are arranged on the 

 proximal two-thirds of the hand in two rows, which coalesce and 

 terminate as a single row at the base of the fixed finger. Fingers 

 imperfect, rather slender, half (?) as long as the hand when perfect. 

 Length of hand from carpal to dactylopodal articulation =2| inches. 



Affinities. — This species difi'ers from its existing representative, 

 N. norvegicus, by its larger size, by the form and magnitude of the 

 tubercles, and by the arrangement of the median rows on the dorsal 

 and palmar surfaces ; in the living form these are placed approxi- 

 mately opposite each other and about equidistant from the inner 

 and outer borders ; in the fossil the palmar is much nearer the inner, 

 and the dorsal nearer the outer border of the hand. 



HemarJcs. — The only portions of this species which have been 

 hitherto determined are the chelae of the first pair of limbs, but 

 the characters which these members afford are so distinctive as to 

 warrant a positive generic reference. 



It is of phylogenetic interest to recognize in this Eocene form 

 the vigorous prototype of one of the most graceful of existing 

 British species, N. norvegicus, and it is of biological importance as 

 affording partial evidence of the kind and degree of modification of 

 character which has taken place. 



I am indebted to the authorities of the York Museum for kind 

 permission to describe this addition to the list of British fossil 

 Crustacea, and I have great pleasure in dedicating this species 

 to the late William Eeed, F.G.S., to whose profuse liberality that 

 museum owes one of the most valuable of the many provincial 

 collections in this country. 



Distribution. — Crag of Boyton — derived from the London Clay. 

 Four specimens exist in the York Museum. 



Genus Gebia, Leach. 



Gebia cltpeatus, sp. nov. (PI. I, fig. 2.) 



Description. — Carapace rather compressed laterally ; length — 

 exclusive of rostrum — nearly twice the metabranchial height. 

 Bostrum produced, broadly lanceolate, deeply grooved dorsally ; the 



