THE 



GEOLOGICAL MAGAZINE. 



No. XLIII.— JANUARY, 1868. 



I. On a New Limuloid Crustacean [Neolimulus falcatus\ 



FROM THE Upper Silurian of Lesmahagow, Lanarkshire. 



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



(PLATE I., Fig. 1.) 



IN a paper which I communicated to the Geological Society of 

 London, Nov. 21, 1866,^ (" On some points in the structure of 

 the Xiphosura, having reference to their relationship with the Eu- 

 rypterida'') I have recorded all the then known genera both of Xi- 

 phosura and of Eurypterida, and in the tables which accompany the 

 first part of my Monograph on the Merostomata,^ I have given both 

 the genera and species with their range in time and space. 



Although it will be seen, by a reference to the last-named work, 

 that none of the Xiphosura have hitherto been found in strata older 

 than the Coal-measures, yet I have pointed out the existence of cer- 

 tain Silurian forms (included by me in the sub-order Eurypterida), 

 which indicate a passage — as it were — between the Eurypteridce and 

 Pterygoti proper, and the Limulidce.^ 



It was with extreme interest therefore, that I obtained from Mr. 

 Kobert Slimon, in September last, the first evidence of the existence 

 of a true Limuloid form of Crustacean from the Uppermost Silurian 

 shales of Lanarkshire. 



It is hardly possible to estimate too highly the persevering labours 

 of Mr. Slimon and his sons in the investigation of these Lesmahagow 

 deposits, and one is led to reflect what an enormous amount of ad- 

 ditional knowledge would result, if other local geologists devoted 

 themselves with the same energy to the investigation of the rocks 

 of their own particular district. 



Unlike the majority of the Crustacea obtained from these deposits, 

 our present acquisition cannot be classed among the giants of those 

 days, the specimen only measuring five and a half lines in greatest 

 length and six lines in greatest breadth. It is preserved upon the 

 extreme edge of a piece of shale, so that, unfortunately, the ultimate 

 segment, as I conceive, and the telson or tail-spine are wanting 

 through being cut off by a cleavage-plane. I have allowed the artist 

 to indicate their probable size in outline, in Plate I. Fig. 1 a ; the rest 

 of the figure, actually preserved in the fossil, being shaded. 



1 See Quart. Journ. Geol. Soc. Feb. 1 867. Vol. xxiii. p. 28. PI. I. and II. 



2 Palseontographical Society, vol. xix. December 1866. 



3 Quart. Journ. Geol. Soc. vol. xxiii. p. 31. PI. I. figs. 3-6. 



VOL. v.— NO. XLIII. 1 



