In a former communication to the “Geologist,” treating of the fossil fauna and flova observed in Lower Eocesie sttata passed through at Dulwich and Peckhem in the constraction of the Great South High Level Sewesu I mentioned the fact of having discovered in a shelly conglomerate, at Dulwich, a new species of the estuarine genus Gyrena which I proposed to call Cyrena, Dulurichieæsis. In sinking the main shaft, at a depth of fifty to sixty, feet this eonglomerate occurred in nodular masses in green shelly sand, intercalated with wedge-like bands of stiff black clay, highly charged with vegetable remains; bat on driving the gallery eastward the conglomerate became regularly bedded, and attained a maximum thickness of four feet, made up plentifully of the shells of Cyrena cumeiformis, C. cordata, C. Dulwichiensis, Melania inquinata, and the new genus Pitharella, now figured and described by Mr. Edwards. I annex a description of the distinguishing generic characteristics of the Cyrena Dulwichiensis, and, as an accompaniment to the figure, some of the prominent peculiarities noticeable in the species.