PROTEIDAE 135 



a number of eggs which were then fastened singly on to the 

 under side of projecting stones in the 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 mm. The larvae 

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

 already much like the adult, except that the fin was not 

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

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

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

 less little stumps.^ 



Tiiplilomolgc rathhuni. — It is of the greatest interest that 

 a subterranean Perennibranchiate 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 Necturus-Vike, ancestors, 

 one in Europe, the other in North America, absolutely 

 independently of each other. The limbs of TyiMomolge are 

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

 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 the pair of 

 united but large opercular flaps. 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 75 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," " the legs are 

 used for locomotion and the animals creep along the bottom of 

 the aquarium with a peculiar 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 them to eat have been futile, as has also 

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



^ See also M. von Chaiivin, ZcitscJu: iviss. Zool. xxxviii. 1883, p. 671. 

 - Nature, Ix. 1899, p. 389. 



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