BOMBINATOB. 141 



2. BOMBINATOR. 

 Merrein, Tent. Syst. Amph., p. 178 (1820), partim. 



Pupil roundish, triangular, or cordiform. Vomerine 

 teeth in two short transverse groups behind the 

 choanjfi. Tongue circular, entire, adherent. No 

 tympanum. Fingers free, toes webbed; outer meta- 

 tarsals separated by web. No palatine bones. Dia- 

 pophyses of sacral vertebra very strongly dilated. 

 Urostyle articulated to a single condyle. 



This genus includes three closely allied species. 

 Two are European ; the third, Bombinator orientaUs, 

 Blgr., inhabits North-eastern Asia, from Manchuria to 

 Northern China. 



Apart from the coloration, the two European 

 species are easily distinguished by the length of the 

 tibia or crus, which is shorter than the foot, measured 

 from the base of the inner metatarsal tubercle, in 

 B. igneus, and as long as the foot or even a little 

 longer in B. pachypus. Males are besides distinguished 

 by the presence in the former and the absence in the 

 latter of internal vocal sacs ; during the breeding 

 season the third finger and one or several of the toes 

 are provided with plates of black horny asperities in 

 B. pachypus, which are never present on those parts in 

 B. igneus. 



Although nearly allied, and actually known to pro- 

 duce fertile hybrids,* the right to specific distinction 

 of the two European forms, so long confounded 

 under the name of B. igneus, is now established beyond 

 contest. 



* That this affords no absolute criterion in mattei-s of specific dis- 

 tinctions is shown, among Batrachians, by the two newts, Molge cristata 

 and M. marmorata, producing the hybrid known as M. biasii, which 

 proves to be fertile for one or two generations at least. 



