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Show 136 DR. J. B. GRAY ON PLAT ASTERIAS. [Feb. /, cou et du thorax, qui n'existe pas dans l'ancienne espece dont le peu de roux qui se trouve melange au cou et a la poitrine est toujours d'une paleur qui ne rapproche en rien de la vivacitcde celle de notre nouvel oiseau ; et il en est de meme pour la teinte grise de la partie superieure que nous n'avons jamais vue aussi tranchee que dans celui de Natal. Quoique les trois exemplaires que nous avons vus, n'aient pas la longue queue qui ne parait qu'a. la saison des amours, nous ne doutons pas qu'a cette dpoque notre oiseau n'en soit aussi pourvu, ce que viendront confirmer les naturalistes qui plus heureux que nous se trouveront a. meme d'en faire l'observation. 6. Description of Platasterias, a new Genus of Astropec-tinidce, from Mexico. By Dr. J. E. G R A Y , F.R.S. & c [Received January 23, 1871.] (Plate IX.) Mr. A. Boucard has lately sent some reptiles and other animals from Tehuantepec in Mexico to the British Museum, among which is a specimen of a Starfish allied to the genus Astropeden, belonging to a form which I do not recollect to have been previously noticed, and evidently very different from any that I have ever before seen. It differs from Astropeden in being much flatter, more like a deeply divided Palmipes, without any marginal tessera and with a single row of marginal spines. It is peculiar in the rays being very broad near the base, and then contracted and separated from each other by deep fissures. PLATASTERIAS. Body much depressed, flat, divided into five flat rays, which are broad near the base and gradually tapering to the ends, suddenly narrowed near the body and separated by deep fissures ; the margins of the rays narrow, sharp-edged, with a single series of very close short depressed mobile spines. The dorsal surface covered with close transverse linear series of short papillae, which are covered at the end with a number of very short spines or paxillce. The under surface with a central longitudinal keel on each side parallel to the ambulacra, with close transverse series of linear ridges, each covered with a series of short close spines; the ambulacra edged with a series of elongate tapering acute spines, and with a tuft of similar spines at the angles of the mouth between the ambulacra. PLATASTERIAS LATIRADIATA, sp. nov. (Plate IX.) Body yellow when dry ; the rays five, flat, twice and a half the length of the diameter of the body, broadly lanceolate. The basal quarter suddenly dilated to its greatest width and then gradually tapering to the end, the greatest width being two-fifths |