432 Afnerican Seashelh 



/4 to % inch in length, fragile, elongate, white in color with a delicate 

 iridescence on the smooth exterior. Posterior and narrower end slightly 

 twisted to the left. This small, tellin-like species is very common in shallow 

 water in sand. M. soiileyetiana Recluz is the same. 



Macoma limiila Dall is very similar in size and shape, although somewhat 

 more elongate, and is distinguished by the finely granular external surface 

 of the valves. Commonly dredged from North Carolina to Florida. 



Macoma constrict a Bruguiere Constricted Macoma 



Florida to Texas and the West Indies. 



1 to 2/4 inches in length, moderately elongate. The posterior end is 

 twisted to the right and is narrowed to a blunt point. Color all white with 

 concentric growth lines stained by the gray periostracum. Common just off- 

 shore. 



Macoma nasuta Conrad Bent-nose Macoma 



Figure 88d 



Alaska to Lower California. 



2 to 3% inches in length, elongate, rather compressed and strongly 

 twisted to the right at its posterior end. Beaks slightly nearer the anterior 

 end. Can be distinguished from other Pacific Coast species by the paUial 

 sinus in the Jejt valve which reaches the anterior muscle scar. One of the 

 commonest species on the west coast and lives about 6 inches below the 

 surface of the mud in quiet waters from shore to 25 fathoms. 



Macoma secta Conrad White Sand Macoma 



Figure 88c 



Vancouver Island to the Gulf of California. 



2 to 4 inches in length. This is the largest Macoma in America and is 

 characterized by the almost flat left valve, rather well-inflated right valve, 

 and by the wide and relatively short ligament which is sunk partially into 

 the shell. There is a large, oblique, rib-like extension just behind the hinge 

 inside each valve. Color cream to white. Common in bays and beaches from 

 shore to 25 fathoms. A small form occurs in protected waters in bays in its 

 more southerly range. 



Students of the Pacific Coast fauna consider M. indentata Carpenter 

 (same range) as a distinct species in which the shell is 1% inches in length, 

 a little more elongate, with a more pointed posterior end, and with a slight 

 indentation on the posterior ventral margin. It may possibly be a form of 

 young secta. M. teniiirostris Dall is even more elongate and may also be a 

 form. 



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