some British Fossil Crustacea. 177 



about three large sharp teeth each ; rostrum large, deeply chan- 

 neled in the middle, sides rising to v.ery prominent keels mi- 

 nutely serrated towards the end, one elongate tubercle on each 

 side of its base ; nuchal furrow strong, ends curved forwards, 

 but only extending about halfway from the middle of the back 

 to the side margin ; beneath and in front of each of its ends a 

 very deeply marked X-shaped sulcus ; surface very closely and 

 minutely granulated, punctured on the cardiac and intestinal 

 region ; ends of the abdominal segments broadly rounded with 

 a small mucronate point directed backwards ; the last two 

 joints with rough transverse scale-like sculpturing^ the others 

 so finely granulated as to appear nearly smooth. 



This species is remarkable for the size and prominence of its 

 sharply angulated cheek-ridges ; the surface, particularly of the 

 abdomen, is more nearly smooth than in the other species which 

 I have seen. 



Common in the Speeton clay of Speeton, Yorkshire. 



{Col. University of Cambridge.) 



Hoploparia gammaroides (M^Coy) . 



Sp. Char. Carapace averaging from the orbit to the posteriw 

 side-margin 2f inches, depth 1^ inch, minutely punctured on 

 the middle of the back, coarsely squamoso-punctate on the 

 gastric region, granulated on the sides, most strongly near the 

 front lateral margins ; nuchal furrow strong, but only reaching 

 halfway down the sides, its middle portion equally distant 

 from the edge of the orbit and posterior margin of the cara- 

 pace, or slightly nearer the former; \-shaped cheek-furrow 

 deep ; rostrum strongly bicarinate, with a ridge-like tubercle 

 about two lines long on each side of its base, and one small 

 tubercle at an equal distance below the first pair at the edge 

 of the orbit ; from a little behind the level of the orbit the 

 cheek is elevated into a strong keel with about three large 

 spinose tubercles, cheeks prolonged as a semicylindrical 

 sheath to the outer antennae half the length of the rostrum : 

 abdominal segments very flat and smooth, the articular ante- 

 rior portion scarcely convex,, and the sulcus dividing it from 

 the posterior portion not very strong, first segment closely 

 punctured like the middle of the thorax, the dorsal portion of 

 the others with the puncta slight and distant, flaps of the tail 

 coarsely squamoso-punctate ; chelce very large, with a rude 

 scale-like sculpturing of the surface, broad one having the 

 hand as wide (li inch) as from the carpus to the base of the 

 moveable finger, four large, short spines on the inner margin, 

 moveable finger longer than from its base to the carpus; car- 

 pus with several thick short spines ; smaller hand as long as 



Ann. ^ Mag. N. Hist. Ser. 2. Vol. iv. 12 



