1014 THE VOYAGE OF H.M.S. CHALLENGER. 



2. Eutymixinimn octonarium, n. sp. 



Eight vertical coluinelL'e slightly curved, thorny. Both horizontal rings equal, octagonal, each 

 armed with eight large, irregularly-branched spines, which on the mitral ring are directed obliquely 

 upwards, on the basal ring downwards. 



Dimensions. — Height of the shell 012, breadth 01. 



Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 



3. Eutympanium coronarium, n. sp. • 



Eight thorny columellse, obliquely descending and curved like a bow, divergent in the upper 

 part, convergent in the lower. Basal ring circular, mitral ring octagonal. Both horizontal 

 rings armed with eight stout thorny spines, which on the mitral ring are smaller and directed 

 obliquely upwards, on the basal ring larger and directed downwards, each with a recurved hook. 



Dimensions. — Height of the shell 0"08, breadth 0'06. 



Habitat.— South Atlantic, Station 332, depth 2200 fathoms. 



4. Eutympanium militare, n. sp. (PI. 82, fig. 11). 



Ten parallel and vertical columellje straight and smooth, cylindrical. Both horizontal rings 

 equal, circular, armed with numerous short conical spines, divergent in all directions. Ten to 

 twenty spines on each ring larger than the others. 



Dimaisions. — Height of the sheU 01, breadth 0'08. 



Habitat. — -Western Tropical Pacific, Station 225, depth 4475 fathoms. 



5. Eutympanium dodecarium, n. sp. 



Twelve vertical columellse, slightly curved, smooth. Mitral and basal rings circular, both 

 horizontal rings armed with twelve stout, irregularly-branched spines, which are prolongations of 

 the columella, and on the mitral ring directed upwards, on the basal ring downwards. 



Dimensions. — Height of the shell 013, breadth 01. 



Habitat. — South Pacific, Station 300, depth 1375 fathoms. 



