TURBINACEA. MOLLUSCA. PYRAMIS. 269 



Py'RAMIS STRIA'TtTLA. 



Shell turreied, dingy-white ; whorls eighty nearly jlat^ with 

 numerous fine., revolving lines ; upper whorls tapering rapidly ; 

 suture distinct. 



Figure 174. 



State Coll., No. 53. Soc. Cab., No. 2360. 



PyVamis striatula, Couthouy ; Bost. Journ. Nat. Tli^i., ii. 101 , pi. 1, f. 6. 



Shell elevated, obelisk-shaped, thick, bluish-white, usually- 

 having a dead, unpolished appearance ; whorls seven to nine, 

 nearly flat, distinctly separated by the suture, a few of the upper 

 ones tapering rather suddenly to an acute point, thus giving it an 

 obelisk shape ; marked with obvious lines of growth, sometimes 

 approaching to varices, and with from twelve to fifteen fine, reg- 

 ular revolving lines, diminishing in number towards the apex ; 

 aperture ovate, acute-angular behind ; outer lip sharp and simple, 

 without any sinus behind ; slightly turned outwards at base, as it 

 joins the regularly arched pillar margin. Length || inch, 

 breadth /^ inch, divergence 23°. 



First found by Mr. Couthouy in the stomachs of fishes caught 

 ofl^ Cape Ann. Several specimens have since been found, but it 

 is by no means common. 



I have employed the genus Py'ramis, not because I would adopt it, 

 but because I know not any established genus under which this shell 

 would come ; and do not wish to confuse, if I cannot correct. The 

 characters of the aperture are like those of the preceding species, but 

 the exterior has a different character. Its aspect is precisely that of a 

 shell sent me as Monoti'gma, Gray ; but I cannot find the plait on the 

 inner lip, from whence that genus derives its name. 



Genus ODOSTOMIA, Fleming. 



Shell conical, elongated; aperture ovate; lips disunited posteri- 

 orly, and sometimes produced anteriorly ; pillar loith a tooth-like 

 fold; operculum horny, sub-spiral. 



