Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/582

 ness of the whole group is many times greater than this, a portion of the series in Venezuela being probably inferior in position to the rocks exposed in Trinidad. A high angle of inclination almost everywhere prevails, the general range of dip being from 30° to the vertical.

After noticing the difficulty which has hitherto existed in deter- mining the age of the Caribbean formation, from the want of fossil evidence, the author stated that he has found undoubted traces of the existence of organisms during the deposition of these rocks. In the uppermost compact dark-blue limestone (No. 4) obscure fossils occur. In the clay-slates and quartz-rocks (No. 3) underlying this limestone there are strings and bands of calcareous matter which sometimes contain fossils. In a portion of one of these strings found by the author about 3 feet below the surface in the decomposed mica-slate forming the soil of one of the valleys, he detected a structure which he regards as of animal origin, and as probably most nearly related to Eozoon. He was unable to detect any traces of tubulation in it, but suggests that this character may have been obliterated, as in the Tudor specimen (Quart. Journ. Geol. Soc. vol. xxiii. p. 257). The chambers are said by the author to be more elliptical than those of Eozoon canadense ; and for this and other reasons he proposed to regard it as a new species, under the name of Eozoon caribboeum.

Associated with this supposed Eozoon, the author has found other remains. These include fragments of coral, some of which are stated to resemble Favosites, although no pores or tabulae could be detected in them. These fragments are thought by the author to have belonged to a minute branching Favosites, which he proposes to name F. fenestralis. Plates and stems of Echinoderms are scattered through the rock. The author particularly described a specimen consisting of five ambidacral plates, with four pairs of pores, and another fragment showing portions of at least twenty ambulacral or pseudo-ambulacral plates, reminding one of those of the Devonian Eleacrinus.

The author has found that the bands of calcareous matter inter- stratified among the slates are seldom devoid of organic remains, except when they are very highly metamorphic. In a finely laminated limestone he found great abundance of obscure fossils, many of which appeared to be remains of Cystidea, whilst others resembled annelid -tubes, like Salterella.

The author suggested that the function of Eozoon in pre-Cambrian times was analogous to that of corals at subsequent periods. He considered that there is the highest probability that the Caribbean series will ultimately prove to be pre-Silurian.

Discussion.

Dr. Carpenter, from the slight examination he had been able to make of the fossils, was unwilling to speak decidedly about them. There was, however, no doubt of numerous organic remains occurring in the rocks, and among them serpuline shells and echinoderms.