ART. 19 



GEEEISr PIT VIPER PROM CHINA STEJNEGER 



While in the southern and lowland form the paired style is recog- 

 nized in all the 32 specimens, the pairs are recorded as " irregular " 

 in 4, among them one of the types of T. albolabris. 



In the northern and highland form, including specimens from 

 central Yunnan, the special modification of the scales bordering the 

 groove and their paired arrangement is the exception. Often some 

 of the scales show a tendency toward such modification, especially 

 posteriorly, and various specimens present intermediate stages be- 

 tween the two typical patterns. However, out of 32 specimens, 19 

 are unmistakably of the Formosan type figured (fig. 2), while 9 

 are clearly of the paired type and 4 more or less irregular. It is 

 rather singular that all the six specimens from Darjeeling as well 

 as one from Sikkim in the British Museum, according to Parker, 

 have the gulars in pairs. 



Fig. 2. — Trimeresuhus gramineds stejnbgbri, 1%X nat. size. «, Top of head; b. side 

 OF head; c, underside op head. No. 2" Sci. Coli/. Tokyo from Taipa^ Formosa, 



COIiLECTED BY T. TaDA 



The pronounced typical style of the northern and highland form 

 is therefore present in more than 59 per cent of the specimens, while 

 of the southern and lowland form about 88 per cent show the paired 

 modification. 



SUMMARY 



It will thus be seen that the four characters alluded to do not 

 trenchantly and in all cases separate the two forms. There is a 

 considerable amount of overlapping. Nor are the characters of equal 

 value, the gular arrangement being the least reliable. Nevertheless 

 in nearly every instance it is possible to refer a specimen to its proper 

 geographical series by a combination of the characters. The conspic- 

 uous exception is the Darjeeling specimen in the British Museum, 

 repeatedly referred to above. 



Under these circumstances it is hardly advisable to treat the two 

 forms nomenclatorially as distinct species, and a trinominal appella- 



