1561 
Genus TtuIIr Kaup 
Archiv Katurges., vol. 24, pt. 1, p. 109, 1858. (Type, 
Trulla cantori Kaup » Plagusia trulla Csntor , virtually tautotypic.) 
Mouth inferior. Lips not fringed. Nostril single on left 
side, before front of lower eye. Ctenoid scales on left side, cv- 
9 
oloid on right side. Lateral lines 3 on left side, none on right. 
Only left ventral present, more or less confluent with anal. 
