490 REPORT OF NATIONAL MUSEUM, 1898. 



each side the sulcus is margined by a thin welt or lip. This is coarsely 

 plicate transversely, the plica? extending to the welt. On the other side 

 the transverse pliciB terminate at a band of tine longitudinal folds. In 

 Ophisaurus the organ is undivided, and there is a welt with one edge 

 and the proximal end free. It is covered with robust papilhe. 

 The genera are otherwise characterized as follows: 



I. A premaxillary foramen; no lateral fold; anterior limb of interclavicle short. 



Anguinie. 



Rudimental posterior limbs (fpheodes VViigler. 



No rudiments of limbs Arujuis Linmeus. 



II. A premaxillary foramen; anterior limb of interclavicle short or wanting; a lat- 



eral fold of the integument. Ophisaurin;f . 



Rudiments of hind limbs only; meatus auditorius open Pseudopus Merrem. 



No limbs; meatus auditorius open; are interclavicle Ophisaurus Daudin. 



No limbs ; meatus open ; no interclavicle Dopasia Gray 



Rudimental limbs; meatus closed Hyalosaurus Glinther. 



III. A premaxillary foramen; anterior limb of interclavicle generally well devel- 



oped; no lateral fold. DiplogloasintB. (Limbs, four. ) 



Feet peutadactyle; frontonasal plates distinct Diploglossiis Wiegmanu. 



Feet pentadactyle ; frontonasal plates united into a single shield . . Celestns Gray 



Feet tetradactyle ; one frontonasal Sauresia G ray 



Feet mono- or didactyle : one frontonasal Panolojius Cope. 



IV. No premaxillary foramen ; anterior limb of interclavicle well developed ; a 



lateral fold. Gerrhonotinit. 

 Interfrontonasal plate and frontonasal plates present. . . Gerrhonolus Wiegmann. 



Interfrontonasal present ; frontonasals absent Mesas2)is Cope. 



Interfrontonasal wanting; frontonasal plates present Barissia Gray 



The geographical range of these genera is as follows: 



Nearctic genera : Ophisaurus, Gerrhonolus. 



Neotropical genera: Opheodes, Diploglossus, Celestas, Sauresia, Panolopus, Gerrho- 

 notus, Mesaspis, Barissia. 



Palearctic genera: Anguis, Psendopus. 

 Paleotropical genera: Dopasia. 

 Ethiopian and Australian genera: None. 



I have examined the osteology of three exotic serpentiform genera, 

 with the following result: 



Anguis fragiUs Linntieus. Described by Heusinger,^ Miiller,- and 

 imperfectly figured by Duraeril and Bibron.^ It is well described and 

 figured by Fiirbringer.* Europe. 



Scapular and pelvic arches jjresent; no limbs. 



Scapular arch. — Interclavicle wanting ; other elements present. Ster- 

 num roughly transverse diamond shaped, with the i^osterior border 

 slightly convex. Ko costal connections. Ossification slight. Clavicles 

 osseous, slender, directed forward medially, and not quite meeting on 

 the median line. Scapula cartilaginous, coracoid osseous. A large 

 coracoid cartilage, which slightly overlaps that of the other side ante- 



'Zeitschr, fiir organ. Physik., Ill, Pt. 5, pi. in, fig. 9. 

 - Tiedemann u. Treviranus, Zeitschr. f. Physiologie, IV, 1831. 

 sErp. G6n., pi. vii, figs. 6, 10. 



^DieKnochen u. Muskeln der schlangeniihnlichen Saurier, Leipzig, 1870, pp. 14, 

 42, pi. I, tig. 9; pi. Ill, figs. 37, 38. 



