ENTOMOCONCHUS. 45 



what compressed posteriorly. Anterior slope 70°; hinder slope 80°. Dorsal and ventral 

 margins slightly convex, the latter bordered by a raised rim. End-view acute-oval ; edge- 

 view long-pyriform. 



Length ; height ; thickness inch. Proportions 14:7:6. 



This rare form occurs to us as a single valve from the Upper Carboniferous Limestone 

 at Vise, Belgium, and we are indebted to M. J. Bosquet, E.C.G.S., for this and other 

 interesting specimens. 



X. ENTOMOCONCHUS, M'Co?/, 1839. 



The bibliographical history of JEnfomoconc/ms is that of its best-known species, 

 B. Scoukri. In 1839 Professor E. M'Coy figured and described as Entomoco7ichus 

 Scouleri, in the 'Journal of the Geological Society of Dublin ' (vol. ii, p. 91, pi. 5, figs. 

 a — e), some large globose Entomostracan specimens which had been obtained by himself 

 and Dr. Scouler from the Mountain-limestone of Clane, Co. Kildare, Ireland. This form 

 had already been recognised as occurring in the Mountain-hmestone of Bolland (Bowland 

 Forest), Yorkshire, by Prof. John Phillips, and was referred to by him in his ' Geology 

 of the Mountain-limestone District of Yorkshire' (1836), pages 240 and 251, as a 

 "Cypridiform Shell," in the Gilbertson Collection but he did not describe it, though 

 he gave sketches of it in pi. 22, figs. 23 and 24, of that work. 



In 1841 five species of Bivalved Entomostraca from the Carboniferous Limestone of 

 Belgium were figured and described by Prof. Dr. L. De Koninck, of Liege, in his 

 ' Memoire sur les Crustaces fossiles de Belgique,' in the ' Mumoires Acad. Royale Belg.,' 

 vol. xiv. At page 16, under the name CytUerina Phillipsiana (fig. 13), we have the 

 peculiar gibbose form common in some of the beds of the European Mountain-limestone, 

 and above referred to as Entomoconchus Scouleri. The foregoing five species, together 

 with one other, were more fully treated and illustrated in his ' Description des Animaux 

 fossiles qui se trouvent dans le Terrain Carbonifere de Belgique' (4to, Liege, 1842-44). 

 Among them De Koninck described his Cypridina Edioardsiana, C. concentrica, C. annu- 

 lata, Cyprella chrysalidea, and Cypridella cruciata. The generic affinities, however, were 

 not well determined, owing to the fact of the peculiar antero-ventral notch in the valves of 

 Cypridina having been omitted in the engraving of Milne-Edwards's typical species (as 

 explained in the 'Monograph of Tertiary Entomostraca of England,' Pal. Soc, 1856, 

 page 9), and the palaeontologist having been thereby misled in collocating the fossil 

 carapaces with their recent analogues. See above, p. 11. 



In 1844 Prof. M'Coy enlarged our knowledge of the Entomostraca of the 



^ Now in the British Museum. 



