444 ANALYSIS OF GENERA. Shell ribbed, ~perculuiii \ EJephant,ulum. .more or less I Caec- ......... Shell ringed, J Anellum. Growth Shell smooth, Fartudum. sively de- Operculam collated. convex ......Brochina. spiral.. ..................... .Meioceras. Shell persis- tent ........................................ .Strebloceras. 4. DESCRIPTIONOF RIAMA,A NEW GENUSOF LIZARDS,FORM- ING A DISTINCT FAMILY.Br DR. JOHNEDWARD GRAY, F.R.S., F.L.S., V.P.Z.S., PRES.ENT. SOC.ETC. (Reptilia, P1. XV.) Mr. Louis Fraser has lately sent to the British Museum a con- siderable series of Lizards, Snakes, and Toads and Frogs from Gua- yaquil, in spirits. Among other interesting species is an aiiriulated Lizard, which, as it cannot be referred to any of the existing families, aiid has a very peculiar external appearance, must at the same time be considered as the type of a new genus and new family. This Lizard belongs to the section of Cyclosazcrm, which have a distinct longitudinal fold along each side like the Zonun2e ; but it differs from the animal of that family in all the scales of the body and tail being elongate, four-sided, placed in transverse rings and regular longitudinal series, like the scales of the rimipJ&6enidce, while the scales of the back and tail of the Zo~zuridaare all rhombic and more or less distinctly keeled. It differs from the Amphisbcenide in having an elongated head, four distinct moderately strong limbs (each furnished with five toes armed with claws), and broad square shields on the central part of the belly and tail. It differs from the genera of the Chalcirle in the positioii of the nostril (which in the genera of this family is large and placed in the suture between the lower edge of the nasal and the upper edge of the labial shield), and in the presence of exposed ears, which in that fa- mily are entirely hidden under the skin. These animals have the general form of the Lizards-their elon- gated head furnished nith regular shields, well developed eyes co- vered with eyelids, well developed legs and feet, and a bifid tongue with acute lobes, combined with small regular scpare or rather elon- gated four-sided scales forming rings round the body. The scales of the different rings are arranged in regular longitudinal series, siiiooth, impressed, not imbricate me over the other, but lihe those of Am- phisbmrta : indeed on looking at ite back it niight he almost taheli for iy 44 ,> an Amphis6m~afurnished with short legs ; but, unlike those animals, the scales of the middle of the belly and the middle of the under side of the body are of the same length, but twice as wide, as the other scales, forming equal-sided square shields like those of the true La- certida. Their general appearance would lead one to the idea that they may form a group intermediate between the BmnpAisbanu and the Zonu- r@fol-m Lizads, but evidently more nearly allied to the latter. Family RIAMIDB, The characters of thc genus. Genus RranqA. Head elongate, with regular shields ; labial shield short, broad. Chin and gullet with large shields. Tongue scaly ; apex bifid ; lobes acute. Nostrils lateral, in the front part of a single plate. Eyes distinct, furnished with eyelids. Ears sunken, covered with small scales. Throat with several distinct collars, the hinder largest. Body and tail elongate, cylindrical ; sides with a narrow impressed groove extending from the avilla to the groin. The scales of the back, sides of the belly, and upper part and sides of the tail, square, elongate, four-sided, narrow, placed in equal-sized regular transverse rings and longitudinal series ; of the middle of the belly and under side of the tail, broader (about twice as broad as the others), square. Legs four, short, moderately strong. Toes 5 * 5 : the front short, subequal, claws short, blniit ; the hind ones unequal ; the inner very short, rudimentary ; the outer elongate, placed lower on the foot than the rest, claws longer, acute. Femoral pores few, distinct. Tail elongate, cylindrical, rather fusiform, tapering to a fine point. Vent with two arched series of squarish shields iii front. The rings of dorsal scales are rather interrupted over the vertebral line : on the nape between the shoulders and on the front part of the back there is a line, or two or three series, of small scales ; but these gradually become fewer and fewer, and in the hinder part of the back the rings of scales are only interrupted by a very narrow sinuous impressed line, which terminates orer the loins. I am not certain whether this interruption of the rings is a character com- mon to the genus, or a peculiarity of the individual under exa- mination ; it is not to be observed on the upper surface of the tail. A very narrow, indistinct, impressed line is generally to be observed in the same situation in the genus Chirotes, and in some specimens of Amphisbenu. The fronts of the fore legs and thighs are furnished with large flat shields ; the rest of the legs, groin, and axilk are covered with small granular scales. The head has three single shields, the second and third being separated by a frontal pair, placed between the hinder parts of the last of the three pairs of superciliaries ; the sides of the head are covered with three pairs of large polygonal shields ; the temples with small polygonal shields. 446 RIAMAUNICOLOK. (Pl. XV. fig. 2.) .Uniform lead-colonrel in spirits ; tail longer than the body and head, tapering to a fine point. Hub. Ecuador (Mr.Louis Fruser). Length : body and head 2+, tail 3+ inches. It may be observed, that though the genera of the family Char- cide all agree in the form and situation of the nostrils between the nasal and labial shields, and in the absonce of the external ear, they present two very distinct forms of scaling, forming at least two tribes. Thus :- 1. The scales elongate, subquadrate, pointed behind ; the scales in the rings alternating with each other, the points of the scales of one ring being opposite to the suture between the scales in the next ring.-Brachypodzna : Bracfiypzis. 2. The scales elongate, subqnadrate, truncated at the end ; tlic scales of the different rings opposite each other, forming longitudinal as well as transverse lines. The ventral and subcaudal shields broader than the rest.--CfiuZcidina : Chalcis-the first having the shield like ChirocolidB and Anadiade, and the second like Cercosauridce and the genus Plianaa here described. Another genus of this family named Bachia, which is not iii the British Museum, is described as having narrow, smooth, six-sided shields on the back, in nineteen longitudinal series. EXPLANATION OF PLATE XV. Fig. I. Argalia oliuacea, P. Z. S. 1847, p. 97. Proiu Venezurla. Pig. 2. Riama unicolor. All natural size. November 9, 1858. Dr. Gray, F.R.S., V.P., in the Chair. The following papers were read :- 1. CHARACTERSOF Fin NEW SPECIESOF AMERICANBIRDS. BY PHILIPLUTLEY SCLATER, M.A. 1. EUCHLORNISFRONTALIS, sp. nov. Psittaceo-viridis, fmntr et gutture $auk ; alis ciiudague intiis nigris, eztus viridi liwi6ntis ;secundariis allro angvste fwmina- .