136 CRUSTACEA. 



In the large, flattened, strongly toothed rostrum, rough spi- 

 nose legs, the small size of the abdomen, with the general form of 

 its little- arched, weak segments, and the undivided outer pair of 

 tail laminae, this genus approaches the recent Galathcea more than 

 any other recent group, differing in its peculiar branchial fur- 

 rows and ridges, meeting at an angle on the middle of the back, 

 &c. The long, dentated rostrum, large, rough, spinose tubercu- 

 lation of the carapace and chelse easily distinguish those large cre- 

 taceous species from the diminutive genera Clytia and Glyphcea 

 of the oolitic rocks with which they have been hitherto con- 

 founded. The type of the genus is the Astacus Leachii (Mant.), 

 to which at least the figures marked f. 1 & 4. t. 29 of the ' Geo- 

 logy of Sussex ' refer (some of the other figures possibly belonging 

 to the E. bj-evimana, M'Coy). The E. Leachii is also well figured 

 and described by Reuss in his ^ Versteinerungen der bohm. 

 Kreideformation,^ and by Geinitz in his ' Char, der Schich. u. 

 Pet. des sachsisch-bohmischen Kreidegebirges.^ It is distin- 

 guished by the very long, straight, narrow fingers of the chelse, 

 which are nearly twice the length of the basal part of the hand, 

 or from their base to the carpus, and set on their inner edge 

 with a row of narrow cylindrical teeth their own length apart ; 

 the whole hand (or penultimate joint and moveable finger) 

 nearly one-fourth longer than the carapace. A second species 

 of large size and remarkable form occurs in the chalk of Burwell 

 and at Maidstone, several specimens of which I saw in the 

 astonishingly beautiful collection of chalk fossils belonging to the 

 Rev. Mr. Image, near Bury St. Edmunds : the hand in this 

 species is much compressed as well as the carpus and arm, and 

 all covered with large scattered curved spinose tubercles (largest 

 on the outer and inner edges of the hand, carpus and arm) with 

 an intermediate smaller tuberculation ; the basal part of the hand 

 is subrhomboidal, slightly longer than its width ; carpus small, its 

 greatest length and width equal, proximal end only half the size 

 of the distal end, abruptly formed by a deep sinus in the proximal 

 half of the inner margin (like that of the right arm of the recent 

 Callianassa suhterranea) ; penultimate or immoveable finger 

 straight, rapidly tapering to an obtuse point, its length only 

 equaling that of the hand from the base of the finger to the 

 carpus j moveable or last finger a little longer, not tapering so 

 rapidly, and incurved at the apex, each finger with a row of 

 blunt hemispherical tubercular teeth less than their diameter 

 apart. Average length of moveable finger 2 inches 6 lines, 

 from thence to the carpus 1 inch 9 lines, width at base of fingers 

 1 inch 9 lines, width of carpus 1 inch 1 line, width at distal 

 end 1 inch 3 lines. I have affixed the name of Enoploclytia 

 Imagei to this, the largest and most interesting of the mesozoic 



