TRANSACTIONS OF THE SECTIONS. 49 



materials to the growing fabric ; so that we may uot erect a rude and barbarous 

 cairn, the memorial of dead opinions, but construct a temple of well-fitted stones, 

 in which we may worship with delight the God of Truth, and be followed in the 

 same pleasing duty by many successors. 



On some New Points in the Structure of Palcechinus. 

 By W. Helliee Bailt, F.L.S., F.G.S. 

 The genus Palachinus — a fossil Echinoderm of great beauty, which is almost en- 

 tirely confined to the Carboniferous epoch — includes several species, all the described 

 forms of which occiur in Ireland. On examining a fine series of these fossils, in- 

 cluding the original figiu'ed specimens in the ' Synopsis of Carboniferous Fossils of 

 Ireland,' for the purpose of comparison, in the collection of Sir Richard Griffith, 

 Bart., the author was fortunate enough to find amongst them one belonging to- 

 the species (P. eler/ans) which was sufficiently perfect to enable him to ti-ace out 

 the arrangement of the plates compo.-^ing the apical disk — an important part of 

 the test or shell, which had not, he believed, hitherto been described. The great 

 difference between these ancient Echini and those of more recent date, consists in 

 the possession hj the former of a much more numerous series of interambulacral 

 plates, and a corresponding larger number of rows of holes, or poriferous zones ; the 

 genus Palcechinus, as far as at present known, having firom four to seven columns 

 of these interambidacral plates, whilst the Echini of the Secondary, Tertiary, and 

 Recent periods are confined to two rows only. It became, therefore, a matter of 

 interest as to whether the plates composing the apical disk woidd exhibit any 

 change corresponding with that of the great increase in the number of the inter- 

 ambulacral plates. By the fortimate discovery of this specimen, it was found that 

 in the Palcechinus the principal plates are the same in number and position, although 

 differing somewhat in their proportions ; there are therefore five genital, including 

 one larger than the others, which appears to be the madreporiform plate, but which 

 is imperfect, and five ocular plates ; the latter being much larger than usual in 

 more recent forms, and the genital shorter in proportion to their breadth ; there 

 are inner circles of ten sur-anal and a similar number of anal plates. The great 

 peculiarity, and most remarkable difference between this part of the structure of 

 Palcechinus and the recent Echinidffi, consists in the double perforation of the ocular 

 and triple perforation of the genital plates, .\nother addition to the sti-ucture of 

 this interesting Palfeozoic Echinus, not hitherto published, is that of the spines, 

 which the author had some time previously observed on a specimen of the same 

 species (P. eleffans), in the collection of the Geological Survey of Ireland, from the 

 same locality, Hook Point, Comity of We.xford, a number of the minute spines still 

 remaining attached to the plates, the principal tubercles on which are seen to be 

 distinctly perforated, and smTOunded by a circle of smaller tubercles. He found 

 these spines to be a little less than the tenth of an inch in length, and, on exami- 

 nation with the microscope, are seen to be longitudinally situated. 



On the Occurrence of Fish Pe^nains in the Old Peel Sandstone at Portishead, 

 near Bristol. By W. Helliee Bailt, F.L.S., F.G.S. 

 The author stated that, having had occasion to \'isit Portishead about two years 

 previously, he was invited to examine the collection of fossils made by the Rev. B. 

 Blenkiron, a gentleman resident in that neighbourhood, now curate of that parish. 

 Amongst those shown to him were some slabs which had been collected from the 

 shingle of the beach. Upon these he observed bones and scales of fish, some of 

 which he was enabled to identify with characteristic Old Red Sandstone species. 

 On examining the cliftj he was successful in obtaining, from the base of a conglo- 

 merate bed, an additional scale to one he had identified as Holojytychius nobilissimus. 

 On a subsequent and recent visit, he made a more detailed examination, collecting 

 other fish remains, of a similar character, associated with plants, from red flaggy 

 beds, exposed on the shore between high and low water. He described the geology 

 of the parish of Portishead as presenting many featm-es of interest, independent of 

 its other local attractions, such as beauty of scenery, &c. Portishead Point, to the 

 north, consists of a steep ridge of carboniferous limestone, the beds dipping at a 

 1864. 4 



