DALL : MOLLUSCA AND BRACHIOPODA. 249 



Section Myurella Hinds, 1844. 



Young with double nodulous band and strong sulcus in front of the snture, 

 shell many whorled, the whorls not constricted, in the adult the nodules obsolete 

 and the band and sculpture as iu Strioterebrum, inner lip callous and elevated. 

 Type Terebra myuros Lamarck. 



See remarks under preceding section. The sulcus is persistent in the adult, 

 though the character of the band alters. 



Section Subula Schumacher, 1817. 



Young with presutural sulcus and band, band and body regularly axially 

 ribbed, the whorl not constricted. Adult shell with many slender whorls, 

 smooth, but with the sulcus persistent; inner lip not callous, other features as in 

 Terebra. Type Terebra dimidiata (Luinc). 



This is the second section of Schumacher's Subula to which the name was 

 restricted by Gray, in 1847. 



Section Abretia H. and A. Adams, 1853. 



Shell small, sculpture uniform, but in the later whorls more or less obsolete, 

 sulcus persistent, whorls axially evenly ribbed, not constricted; young acute, 

 adult subcyliudric ; columellar lip callous : the posterior angle of the aperture 

 compressed into a sort of channel. Type Terebra cerithina Lamarck. 



Section Oxymeris Dall, 1900. 



Shell large, heavy, acute, the later whorls rapidly enlarging ; the young as in 

 Subula, the sulcus not persistent in the adult, which has the later whorls smooth. 

 Type Terebra maculata Lamarck. 



This is Acus Gray, 1847, not of Edwards, 1771. 



Subgenus (and section) Acuminia Dall. 



Young with flat axially regularly ribbed whorls, blunt at the suture without 

 sutural band or sulcus, sliell slender, many whorled, the adult smooth, the colu- 

 mellar lip bare, with no canal, but a deep siphoual sulcus. Type Terebra lanceata 

 (Linne). 



This section of Subula is remarkable for the total absence of the presutural 

 sulcus. 



HASTULA Adams. 



Subgenus Hastula H. and A. Adams, 1853. 



Shell small and slender, the sculpture similar in young and old; no presutural 

 band or sulcus, no canal, suture appressed, sculpture of fine axial wrinkles and 

 feeble spiral striae, whorls flattish, spire acute, columellar lip witli a tliin callus, 

 the posterior angle of the aperture channelled ; colors usually dark and lurid. 

 Type Terebra strigillata Lamarck. 



This is a widely distributed group of peculiar sculpture and coloratiou, repre- 

 sented by closely similar species in nearly all the tropical seas. 



