140 BRITISH FOSSIL CRUSTACEA. 



Species 2— EURYPTERUS LANCEOLATUS :— Salter. PL XXVIII, figs. 1, 2, 3. 



Himantoptervs lanceolatus, Salter. Quart. Journ. Geol. Soc, 1856, vol. xii, p. 32, 



— woodcut, p. 28, fig. 5. 



Eurypterus lanceolatus, Salter. Mem. Geol. Surv., 1859, Mon. I, p. 65, pi. i, fig. 17. 



— — H. Woodward. Geol. Mag., 1864, vol. i, pi. v, figs. 7, 8, 



and 9, p. 107. 



— chartarius, Salter. Quart. Journ. Geol. Soc, 1859, vol. xv, p. 234. 



This species was first noticed by Mr. J. W. Salter, under the generic appellation of 

 Himantopterus, in a paper on some new Crustacea from the Uppermost Silurian Rocks of 

 Lesmahagow, Lanarkshire, read before the Geological Society, November 21st, 1855. 



At that time only the penultimate segment and the telson were known. 



In 1859, Mr. Salter described eight species of Eurypterus, from the Upper Ludlow 

 Rocks and the Old Red Sandstone, but he did not refer to E. lanceolatus in that paper. 



Of the seven species there noticed for the first time, two, namely, E. Symondsii, and 

 E. megalops, are now referred to Stylonurus (see ante, p. 124). Four others, viz.: E. 

 pygmceus, E. acuminatus, E. linearis, E. abbreviatus, are still retained, whilst the seventh 

 and last, named by the author E. chartarius, Mr. Salter some years ago, in reply to 

 my inquiries concerning it, kindly informed me that he no longer considered to be a dis- 

 tinct species, but only an obscure specimen of E. lanceolatus. In this opinion I must 

 acquiesce, as I have not been able to see the original specimen referred to in Mr. Salter's 

 description (but not figured by him). 



In the 'Memoirs of the Geological Survey' (1859), Monograph I, "On the genus 

 Pterygotus" by Prof. Huxley and Mr. J. W. Salter, the entire body, with the swimming- 

 feet, of a specimen of Eurypterus lanceolatus is described and figured (p. 65, pi. i, fig. 

 17); but, owing to the imperfect state in which the fossil is preserved, it was impossible 

 to give a very detailed description of the separate parts, or even to be quite certain (except 

 from the spine-like form of the caudal joint) that it was a true Eurypterus ; it was the 

 only specimen then known. 



Mr. Slimon, of Lesmahagow, from whom all the Lanarkshire specimens of Eurypterida 

 have been obtained, has laboured on incessantly since the discovery of the beds in 1851, 

 and has increased our knowledge of these remarkable Crustaceans by more perfect 

 specimens from year to year. 



The British Museum lately acquired, among other specimens, the impression and 

 counterpart of a very beautiful and nearly perfect example of Eurypterus lanceolatus from 

 this locality. The specimen measures only 4 inches in length, and barely 1 inch across 

 the fourth and widest thoracic segment. (See PI. XXVIII, fig. 2.) 



