408 Mr. G. A. Bouleuger on the Several species, among them our most common starfish {Asterias ruhens), I have been unable to examine. The material of some of the species was rather scanty and was from a single locality only. This was the case with Bentho-pecten spinosus and Dytaster agassizi. The specimens examined of these two species (see the table, p. 402) have a disc-radius of 5-10 mm. and 6-12 mm. respectively*, and seem to belong to the same year-class (group II.). The question regarding the age of the starfishes therefore needs further investifjation. XL. — Synopsis of the American Species of Rana. By G. A. BouLENGER, F.R.S. (Published by permission of the Trustees of the British Museum.) I. Toes pointed or with slightly swollen tips. A. Glandular dorso-lateral fold absent or flat and ill-defined, or, if narrow and prominent, not extending to the hip ; tympanum at least f diameter of eye, usually much larger, especially in males ; tibia 2J to 4 times as long as broad ; toes f to entirely webbed; outer metatarsals separated by web nearly to the base ; nasal bones in contact with each other or narrowly separated. 1. Male with internal vocal sacs; dorso-lateral fold absent or flat and very indistinct. Vomerine teeth between the choanse (rarely just behind them) ; first finger as long as or a little longer than second ; tibio-tarsal articulation reaching t^-mpauum or eye ; heels meeting or slightly over-lapping when the hind limbs are folded at right angles to the body; tibia 2^^ to 2^ times in length from snont to vent ; tip of fourth toe free ; no dorso-lateral fold R. catesbiana, Shaw. Vomerine teeth between the choanae ; first finger a little shorter than second ; tibio-tarsal articulation reaching tympanum * The material of Benthopecten spinosus has not a maximum; of Dytaster agassizi, on the other hand, there is a marked maximum at 9-10 mm, comprising 18 individuals (or 52*9 per cent, of the total number).
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