TIIR I5ATRACIT1A OF NOUTII AMFUIOA. 



59 



the middle point oftlic axis. Yonnjier specimens appear to liave sliorter 

 tails. 



Tliei'c is considerate diviMsity in tiic cniv*', of the tiansverse series 

 of palatine teeth. In ncnirly all more northern specimens the central 

 row is formed of two arcs, concave anteriorly, more or less continuous 

 with the lateral, which are anterior and convex anteriorly. The two 

 central arcs arc continuous at their inner ends, forminj;' an inveited 

 an^ie on the axial line. Sometimc^s, however, as in mosr of the 

 sptuMmens from Prairie Mer lioujje, tins central anslc is wantiu}?, and 

 there is only a sinjjle arc or curve, (loncave anteriorly. In tlui type 

 spiMMmi'u described this central row of tiietli is nearly or (piite strai};ht 

 (which is quite apt to ho the case in v(M'y large ones), while in one 

 specimen of No. U'tSi it is convex anteri(>rly. The transverse extent 

 of this middle line of teeth varies. Sometimes there is «;(iite an interval 

 hetwi'cn it and the lateral, while in 31).'>(>, from New Yo k, they are con- 

 tinuous without ai>pre('ial>le interruption. 



There are no very great variations in the pattern of coloration. (Gen- 

 erally the outer surface of the limbs is colored like the back, in which 

 cas(^ there are one or mon*, large, rounded light spots. The under parts 

 aie generally dark bluish; the sprinkling of small whito specks on the 

 sides and beneath varies considerably in prominence. Tlie large dorsal 

 spots are always nearly circular, and vary in number, generally only one 

 series «)n ea(th sidt*. 



In living specimens from Carlish', Pa., the iris is dark brown, without 

 metallic color, scarcely distinguishable from the jiupil. The color of 

 the animal above is adeep anthracite black; beneath, dull livid. On 

 ea(!h side the <lorsal line is a series of large, nearly circular, gamboge- 

 yellow spots, somewhat symmetrically disposed. These vary from !(► to 

 L'(» from head to tail, and sometimes are laiger than the eye ; usually 

 about its size. On tiie sides and beneath are sparingly scattered small 

 bluish-white si)e(^ks. The spots, both yellow and bluish-white, are some- 

 times found on the legs. 



In youngei' individuals tiie yellow sfiots are brighter and the black 

 ground deeper. — 8. F. I>. 



Professor IJaird (I(M>nographic Etn-ycloiia'dia, 1S,51,) thus describes 

 the reproduction of this spcM'ies : 



' ICarly in April, or towards the (Mid of Miirch, large masses of gelati- 

 nous matter may be observed in ditches, jiools of water, or mountain 

 streamlets, which on closer inspection will be found to consist of a num- 

 ber of hollow spheres, about a quarter of an inch in diameter,embedded 

 in or combined together l>y a perfectly transparent .jelly. Within each 

 sphere is a, dark obje(!t, a sph iindal yolk, which in the course of some 

 days becomes (considerably elongated and exhibits signs of animation. 

 Omitting, as unsiiited to our pages at present, any ac(^ount of the em- 

 bryonic development of tin^ animal, we resume its history at the time 

 when its struggles have freed it from the shell of the sphere in which it 



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