TROTEIDAE I 35 



a number of eggs which were then fastened singly on U> ihe 

 under side of projecting stones in tlie water. The pale yellow 

 yolk measured 4 mm. in diameter and was surrounded by a 

 cover of 1 mm. in thickness, besides an outer gelatinous mantle, 

 so that the whole egg measured about 11 nnu. The larvae 

 were hatched after 90 days ; they were 22 mm. long, and 

 already much like tlie adult, except that the tin was not 

 restricted to the tail, but extended over the last (quarter of the 

 trunk, and that their eyes were still visible. The fore-limljs 

 were already typical in shape, but the hind-limbs were still toe- 

 less little stumps.^ 



Tj/plilomolge rathhuni. — It is of the greatest interest that 

 a subterranean Perenuibranchiate newt, in all respects closely 

 allied to Proteus, has recently been discovered in Texas. There 

 can be no doubt that similar conditions of life have produced 

 these closely resembling forms from JVectur us -like ancestors, 

 one in Europe, the other in North America, absolutely 

 independently of each other. The limbs of Ti/pJdomoIge are 

 long and very slender, the four fingers and five toes are thin, 

 free and pointed. The head is large, the mouth square. The 

 eyes are completely hidden and the whole animal is colourless 

 and white. The tail is furnished with a dorsal and a ventral 

 fin. The very deep gular fold is nothing but tlu* pair of 

 united but large opercular fiaps. The three pairs of gills are 

 remarkable for their blade -like stalks, while the gill -lamellae 

 proper are short and restricted to the tapering ends. Total 

 length about 7"' mm., of which the head measures 15, the tail 

 32 mm. 



This peculiar creature inhabits subterranean caves in Texas, 

 to judge from the fact that all the specimens hitherto known 

 have come up with the water of an artesian well 188 feet 

 deep, near San Marcos. According to Blackford,- "tlie legs are 

 iised for locomotion and the aninials creep along tlie bottom of 

 the aquarium with a p>eculiar movement, swinging the legs in 

 irregular circles at each step. They climb easily over the rocks 

 piled in the aquarium, and hide in the crevices between them. 

 All efforts to induce tliem to eat liave been futile, as lias also 

 been the case with blind cave-fish in captivity, and they are 



' See also :\I. von Cluuivin, ZcitscJu-. v:iss. Zool. xxxviii. 1S83, p. 071. 

 - Nature, Ix. 3899, p. 389. 



