译文示例：噝蝰屬成員的體型十分極端,既有相當細小的納米比亞侏膨蝰(B. schneideri),其體長最長只有約28厘米,也許是世界上最小型的蝰蛇;也有相當巨型的加蓬噝蝰(B. gabonica),其體長可以長達2米以上,是世界上最重的蝰蛇。 ↔ Size variation within this genus is extreme, ranging from the very small B. schneideri, which grows to a maximum of 28 cm (11 in) and is perhaps the world's smallest viperid, to the very large B. gabonica, which can attain a length of over 2 m (6.6 ft) and is the heaviest viper in the world.