30 FOSSIL MALACOSTRACOUS CRUSTACEA. 



nuchal furrow strongly marked, and its lateral portion extending further forwards than in 

 most of the species. Abdominal segments more finely and evenly granulated than the 

 carapace. Professor M'Coy states that " the last segment and middle tail-flap have a 

 much coarser, flattened, or squamous tuberculatum ; the transverse suture of the outer 

 tail-flap strongly marked, from the great thickness of the basal portion ;" of this I am 

 unable to speak from my own observation, as in all the specimens I have seen these parts 

 are wanting or imperfect. The anterior legs are very unequal, almost as much so as in 

 H. longimana. The arm is tuberculated, with a row of a few large tubercles on the upper 

 side ; it is much widened towards the distal extremity, where it is about half as broad as 

 it is long ; both the hands are very much flattened, the larger twice as long as it is broad, 

 tuberculated, and armed with a row of large tubercles along the inner edge ; the fingers 

 about as long as the hand, the immoveable finger almost falcate, depressed in the middle 

 throughout its length ; the prehensile margin strongly tuberculated ; the immoveable 

 finger broad and curved, but less so than the other, and armed with similar tubercles. 

 The smaller hand roughly granulated, the inner edge with a series of tubercles as in the 

 larger ; the fingers twice as long as the hand, very slender, the immoveable one much 

 flattened and slightly curved; the moveable one less flattened, smaller, and also slightly 

 curved. 



Length of the whole body C'5 inches ; length of the carapace, from the margin 

 of the orbit, 2'5 inches; breadth L6 inch; length of rostrum 0'9 inch; length of larger 

 hand and fingers 4*2 inches; breadth T5 inch; length of smaller hand, with the fingers, 

 5*2 inches, the fingers occupying more than two thirds of the length. 



From the upper Greensand in the Isle of Wight, and near Devizes, in Wiltshire. 



Obs. This fine species was first discovered by Mr. Saxby, in the upper Greensand at 

 Bonchurch, in the Isle of Wight, and described in the ' Annals of Natural History' by 

 Mr. M'Coy, who dedicated it to the discoverer. The large specimen figured in Plate VIII 

 is in Mr. Cunnington's collection, and is from the Greensand of Wiltshire ; and the hands 

 represented in the same plate belong to another fine example, collected by Mr. Norman, of 

 Ventnor, and now in the British Museum. With the exception of H. scabra, it is the 

 largest species of the genus with which we are yet acquainted. 



Genus — Astacoues, Bell. 

 Astacodes falcifer, sp., Phillips. Plate IX, figs. 1 — 6. 



MyEKIA FALCIFEtt, Pllill. 



Of this remarkable species scarcely sufficient data exist for a satisfactory description ; 

 yet the remains which have come into my hands indicate not merely the specific but the 



