NO. 131-. SYNOPSIS OF THE ASTARTIDyR-DALL. 043 



ventral margin in the adult merely striated. It is the hajihil of many 

 authors and is figured under that name in Binney's Gould, 1870, and 

 regarded as a variety of A. cmnjyressa by Jeffreys. 



ASTARTE (LAURENTIANA Lyell, 1845, var.?) SOROR Dall. 



Type in the Leda clays and other Pleistocene bed.s of ea.stei-n 

 Canada and New England; variety soror, from m^ north latitude 

 through the Arctic waters southward to the Gulf of St. Lawrence in 

 5 to 90 fathoms. 



The recent shell is more trigonal, larger, and the concentric sculp- 

 ture coarser than that of the typical Pleistocene fossil. I adopt the 

 above varietal name for the recent form until more is knoM-n. but I 

 suspect the species are distinct. 



LIST OF THE SPECIES OF THE WESTERN COAST. 

 ASTARTE POLARIS Dall, 1903. 



Kyska Harbor, Aleutians; Constantine Harbor, Amchitka: and 

 near the Shumagin Islands, in 10 to 5.S fathoms, mud or sand, bottom 

 temperature 41^ to 45- F. Also in Baffin's Bay, on the Greenland 

 coast. 



This is the only tvpical Astarte so far identified on the north we.-^t 

 coast. 



ASTARTE LONGIROSTRA D'Orbigny, 1847. 



Falkland Islands, D'Orbigny; Straits of Magellan, in 20 to 61 fath- 

 oms, bottom temperature 48° F. 



The A. magellanica Smith, 1881, judging from the specimens dredged 

 by the U. S. Fish Commission steamer Alhatross, varies so that the 

 distinctions relied on to separate it from ^4. longlrostra disappear in a 

 good series. The name magellanica might, however, be retained in a 

 varietal sense for the specimens with more pronounced sculpture and 

 less protracted beaks. This is the only species recorded from the 

 southern hemisphere. 



Section TRIDONTA Schumacher. 



ASTARTE ROLLANDI Bernardi, 1858. 



Avatcha Bay, Kamchatka, and eastward through the Aleutian and 

 Pribilof Islands, and along the Alaskan coast to Prince William Sound, 

 in 8 to 27 fathoms. 



Suborbicular, nearly smooth, large and heavy, with dark chestnut- 

 brown periostracum, which in the adults is dehiscent on drying. This 

 specie., takes the place in the Avestern fauna occupied ])y .1. castanea 

 on the eastern coast, and, like it, has a pale oblique variety {I <>.>•> a Dall, 

 1903), which is found on oceanic islets, Chika, the Semidis, and Mid- 

 dleton, in 12 to 25 fathoms, sand. 



