very like a Cyclas." He adds, however, that it must be an ocean production notwithstanding, seeing that all its contemporaries in England, Scotland, and Russia, whether shells or fish, are unequivocally marine.
With the exception of two of the figures in Plate X., the figures of the Cephalaspis and the Holoptychius, and one of the sections in the Frontispiece, section 2, all the prints of the volume are originals. To Mr. Daniel Alexander, of Edinburgh, a gentleman, who to the skill and taste of the superior artist, adds no small portion of the knowledge of the practical geologist, -I am indebted for several of the drawings; that of fig. 2 in Plate V., fig. 1 in Plate VI., fig. 2 in Plate VIII., and figs. 3 and 4 in plate X. I am indebted to another friend for fig. 1, in Plate VII. Whatever defects may be discovered in any of the others, must be attributed to the untaught efforts of the writer, all unfamiliar, hitherto, with the pencil, and with by much too little leisure to acquaint himself with it now.