In the Upper Silurian of Lanarkshire. 3 



Not being able to refer tbe Lanarkshire specimen to any previously 

 described genus oiXiphosura, I propose to name it Neolimulusfalcatus.^ 



I shall not now venture to discuss the affinities of the Xiphosura with 

 the Trilohita, a point on which I am deeply interested ; first, on account 

 of want of information as to their appendages, and secondly, because 1 

 believe that a better knowledge of the larval stages of the recent Limulns 

 is essential to a true explanation of these earliest representatives of the 

 group in past time. Dr. Anton Dohrn of Jena, and Prof. 0.0. Marsh 

 of Yale College, Ot., and several other able naturalists have pro- 

 mised me their aid in this interesting inquiry, which, to be carried 

 out in a proper manner, necessitates a temporary residence on the 

 N.E. Ooast of North America or the coast of China or Japan, where 

 living King-crabs abound. 



EXPLANATION OF PLATE I., Fig. 1, la. 



Fig. 1. Neolimulus falcatus, H.Woodw. Natural size (the tail- spine and last segment 

 restored) from the Uppermost Silurian shales of Lesraahagow, Lanarkshire. 

 Fig. la. The same magnified four times. 



The original specimen is now in the British Museum. 



II. — On a new Brachyurous Ckustacean {Frosopon mammillatum), 

 FROM THE Great Oolite, Stonesfield. 



By Henry Woodward, F.G.S., F.Z.S. 



[PLATE I., Fig. 2.] 



AMONG the new Oolitic Crustacea to which I drew attention at 

 the meeting of the British Association, Dundee, was a species 

 of Prosopon from the Stonesfield Slate. 



This genus was proposed by H. von Meyer, in 1835, for certain 

 minute forms of Crustacea from the Upper White Jura of Oerlinger 

 Thai, and other localities in Germany, from whence he has described 

 twenty-nine species, and in addition to these, one from the Lower 

 Oolite, three from the Coral Rag, and one from the Neocomian 

 (see PalcBontographica, for December, 1860, vol. vii., p. 183, pi. xxiii.) 



In it, however, are included forms belonging to a very distinct 

 family which cannot be placed with the Corystidce. A similar form 

 to these, from our own Greensand, has been figured and described by 

 Professor Bell in his Monograph on the Fossil Malacostracous 

 Crustacea (Palseontographical Society, 1862, Part ii., p. 9, pi. ii.), 

 and is correctly referred by him to the FinnotheridtB, under the 

 generic name of PlagiopJithalmus. 



I would suggest that into this genus of Bell's should be removed, 

 all those species at present included under the genus Prosopov, 

 which have " an evenfy egg-shaped carapace with the front slightly 

 produced and bent downwards, the surface nearly smooth, and 

 marked by two shallow transverse furrows nearly parallel to each 

 other, the orbits very small, elongate-oval, and placed obliquely 

 within the margin, appearing as if pierced in the substance of the 

 carapace" (Bell, op. cit. p. 9). 



^ j/eos, young, in allusion to its size, and also its early appearance in time (and 

 limulus) ; axi^falcatus from the sickle-like form of the hody-segments. 



