Scolopendrella in habits resembles chilopods, being found in company with Geophilus burrowing deep in light sand under leaves, or living at the surface of the ground under sticks or stones. It is very agile in its movements, and is probably carnivorous. It was considered by Haase to be eyeless, but the presence of two ocelli has been demonstrated both by Grassi and by Schmidt. Whether the pigment and corneous facet are present is not certain. The embryology is entirely unknown (although Henshaw reports finding a hexapodous young one), and it need not be said that a knowledge of it is a very great desideratum. It is most probable that the young is hexapodous, since the first pair of limbs are 4–jointed, all the rest 5–jointed; while Newport, and also Ryder, observed specimens with nine, ten, eleven, and twelve pairs, and Wood-Mason confirms their observations, “which prove that a pair of legs is added at each moult,” and he concludes that the addition of new segments “therefore takes place in this animal by the intercalation of two at each moult between the antepenultimate and penultimate sterna, as in the Chilognatha, and as also in some of the Chilopoda.” There is but one family, Scolopendrellidæ, and a single genus, Scolopendrella, which seems to be, like other archaic types, cosmopolitan in its distribution. Our commonest species is _S. immaculata_ Newport, which occurs from Massachusetts to Cordova, Mexico, and in Europe from England to the Mediterranean and Russia; Mr. O. F. Cook tells me he has found a species in Liberia, West Africa. The other species are _S. notacantha_ Gervais, Europe and Eastern United States; _S. nivea_ Scopoli (_S. gratiæ_ Ryder), Europe and United States; _S. latipes_ Scudder, Massachusetts. LITERATURE ON SCOLOPENDRELLA =Newport, George.= Monograph of the class Myriopoda, order Chilopoda. (Trans. Linn. Soc. xix, pp. 349–439, 1 Pl., 1845.) =Menge, A.= Myriapoden der Umgegend von Danzig. (Neuste Schriften der naturforsch. Gesell. Danzig. iv, 1851.) =Ryder, John H.= Scolopendrella as the type of a new order of articulates (Symphyla). (Amer. Nat., May, 1880, xiv, pp. 375, 376.) —— The structure, affinities, and species of Scolopendrella. (Proc. Acad. Nat. Soc. Phil., pp. 79–86, 1881, 2 Figs.) =Packard, A. S.= Scolopendrella and its position in nature. (Amer. Nat., 1881, pp. 698–704, Fig.) =Muhr, Jos.= Die Mundtheile von Scolopendrella und Polyzonium. Prag, 1882, 1 Pl. =Mason, J. Wood.= Morphological notes bearing on the origin of insects. (Trans. Ent. Soc. London, 1879, pp. 145–167, Figs.) —— Notes on the structure, post-embryonic development, and systematic position of Scolopendrella. (Ann. and Mag. Nat. Hist., July, 1883, pp. 53–63.) =Latzel, Robert.= Die Myriapoden der osterreichisch-ungarischen Monarchie, ii, Wien, 1884, pp. 1–39, Pls.