84 



BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



Test subcorneal, troehoid, dorsal side forming a cone, bluntly 

 pointed, of variable height, ventral side flattened or very slightly 

 concave, consisting usually of 6 or 7 chambers, of peculiar shape,, 

 widest at the outer border, thence contracted, widening again, and 

 finally contracted again, tapering toward the center, where all are 

 united; chambers separated by a definite depressed area; wall coarsely 

 perforated on the dorsal side, on the ventral side the pores confined 

 to the middle of the chambers; aperture at the margin of the base 

 of the last-formed chamber, the thin extensions of the inner end of the 

 chamber often arch leaving large openings at either side into a central 

 umbilical cavity ; color of the earlier portion reddish-brown, the later 

 part white. 



Diameter up to 0.75 mm. 



This is one of the common and characteristic species of the West- 

 Indian region, and its range extends to the Indo-Pacific and the 

 Mediterranean. The two names given by d'Orbigny were to dis- 

 tinguish the higher spired forms from the lower ones. A study of 

 abundant West Indian specimens seems to show that this difference- 

 is one of degree only, and that there are all gradations in shape. 

 The name squammosa takes precedence as it is earlier both on page 

 and plate. 



Cymbaloporetta squammosa — Material examined 



