Mr. W. H. Baily on some Coal-measure Crustacea. 109 



still further confirmed my views with regard to the advisability 

 of separating them from Limulus; and, on reconsideration, I 

 preferred adopting the appropriate name oi Belinurus, which was 

 applied by Konig to one of the most common species, in pre- 

 ference to that under which I had formerly proposed to group 

 them. 



In the Explanation of Sheet 137 of the Maps of the Geological 

 Survey of Ireland*, I have given a short account of the fossils 

 from the Coal-measures of this district, which includes a notice 

 of these remarkable Crustacea from Bilboa, after visiting the 

 locality, when I was fortunate enough to obtain the very perfect 

 specimen named by me Belinurus Regime, and represented at 

 PI. V. fig. 1 A.t 



On another visit, a still more perfect specimen (fig. 1 B) was 

 obtained by the gentleman who accompanied me on that occa- 

 sion, Mr. John Edge, to whom I am indebted for that and the 

 loan of other specimens which have materially assisted me in 

 drawing up these descriptions j. 



CRUSTACEA. ENTOMOSTRACA. 



Legion PCECILOPODA. Order Xiphosura. 



Genus Belinurus, Konig. 



Etym, BeXoy, a dart ; oipa, the tail. 

 Gen. Char. — General form suborbicular. Head or cephalic 

 shield semicircular, slightly arched; the central portion {//la- 

 hella ?) prominent and declining towards the circumference, 

 surrounded with a flattened margin, and terminating at its pos- 

 terior angles in long spines. Body composed of five segments, 

 which terminate in spines and diminish gradually towards the 



* Explanation of Sheet 137, Geol. Survey of Ireland, Palaeontological 

 Notes, pp. 12-14. 



t Since writing this paper for the British Association, I found that 

 Pictet, in his 'Traite de Paleontologie,' ed. 2, 1854, had anticipated me by 

 removing these Crustacea (as I had proposed to do) from the genus Limulus, 

 restoring them to that of Belinurus, with the following remarks : — 



" Les Belinurus, Konig, different des deux genres precedents par I'arti- 

 culation de la queue, et surtout parce que le bouclier abdominal presente 

 deux sillons longitudinaux qui lui donnent une ressemblance avcc Ic corps 

 des Trilobites." The following is from his classification of Crustacea : — 



Order XIPHOSURA. 

 Genus 1. Limulus. I Genus 3. Belinurus. 



Genus 2. Halycine. | Genus 4. Pterygotus. 



+ I also take the opportunity to acknowledge the kind assistance I have 

 received from Benj. B. Edge, Esq., J. P., of Clonbrock House, Crettyard, 

 near Carlow, who has aided me, on the several occasions of my visits, 

 with valuable information and the loan of specimens. 



