PHYLOCENY OF FUSUS AND ITS ALLIES. 37 



strong' ones are visil)le at tirst, with a fourth one just helow tlie upper 

 suture. (The spirals do not begin as abruptly as in other species, 

 for they are faintly shown on the last portion of the protoconch, where 

 they are visible between the riblets, and even afifect the last of the 

 riblets themselves.) Intercalated spirals appear in the second whorl 

 of the conch. The whorls are ventricose and at first very closely 

 coiled, so that the suture in some specimens is scarcely impressed 

 below the line of the whorls. In the fifth or sometimes the sixth 

 whorl the shoulder becomes flattened, while frequently a strength- 

 ening of the central spirals still further accentuates the angularity. 

 Sometimes from the strengthening of two spirals a bicarinate aspect 

 is given to the shell, which later, from' the subsidence of the lower one, 

 gives way to a unicarination. 



With the appearance of the angulation the ribs become fainter on 

 the shoulder, and in the next whorl disappear altogether. The 

 nodules, however, continue on the keel, becoming somewhat com- 

 pressed vertically. In the final whorl, the vertically compressed 

 tubercles are strong, and the shoulder is nearly flat. The primary 

 spirals are strong, the secondary spirals are weaker, thus producing a 

 distinct alternation. Sometimes compound intercalation occurs. 



In one of the specimens from the Philippines (Acad. Sci.) the 

 angulation never becomes as pronounced as in the normal shells. The 

 shoulder remains convex, the tubercles disappear on the last portion 

 of the final whorl, are replaced by a carina, and finally are only 

 represented by a thickened spiral. This variety (the coins of the 

 series), leads to F. clostcr. A similar individual, labeled F. bcckii from 

 Japan occurs in the Haines coll. Am. Mus. of Nat. Hist.* 



Three specimens in the Jay collection of the American Museum 

 (7975) almost completely represent F. closter of the West Indies, but 

 they are labeled from the Red Sea. The last whorl is round, and the ribs 

 on it are absent. The early whorls clearly show the distans features, 

 but subdued. The later whorls become more rounded, and though a 

 keel (or two) continues for some time, the round outline is more pro- 

 nounced than any angularity. 



This variety appears to be developed independent of the West 

 Indian F. closter, which was developed from the West Indian repre- 

 sentative of F. distaus. The European clostcr type should have a 

 distinct varietal name. 



The American representatives of this species are generally slightly 

 more accelerated than those from Indo-Pacific waters. They appear 



* Citation of localities on labels of modern shells can seldom be trusted- 

 Dealers and collectors will give as the locality the habitat of the species with 

 wliich they identify their shell. Thus a wrong identification means generally a 

 wrong locality. Examples of this may be found in all our large museum col- 

 lections. 



