I50 BULLETIN OF THE BUREAU OF FISHERIES. 



Callocardia morrhuana (chart 



146) Prince Edward Island to Florida. 



Petricola pholadiformis (chart 



147) Prince Edward Island to Nicaragua. 



Tagelus gibbus (chart 148) Cape Cod to Brazil. 



Tellina tenera (chart 149) Prince Edward Island to Barbados. 



Macoma tenta (chart 150) Cape Cod to Haiti. 



Cumingia tellinoides (chart 152) Cape Cod to south Florida. 

 Mulinia lateralis (chart 154). . . .New Brunswick to Texas. 

 Lyonsia hyalina (chart 157) . . . .Nova Scotia to Texas. 

 Corbula contracta (chart 159). . Cape Cod to Jamaica. 



Of approximately equal range north and south (7). 



Soletnya velum (chart 136) Nova Scotia to North Carolina. 



Astarte undata (chart 138) Gulf of St. Lawrence to Cape Hatteras. 



Astarte castanea (chart 139). . . .Nova Scotia to New Jersey and off Hatteras (deep). 



Ensis directus (chart 151) Labrador to Texas. 



Cochlodesmaleanum (chart 156) Nova Scotia to Hatteras. 

 Clidiophora gouldiana (chart 



158) Nova Scotia to New Jersey (North Carolina?). 



Mya arenaria (chart 160) Arctic Sea to Miami, Fla. 



It will be seen that exactly one-third of these species have been listed as predomi- 

 nantly northern, while very nearly one-half are to be regarded as southern. The seven 

 remaining species are not assignable to either division. 



The following species are recorded from our dredgings, but were not taken frequently 

 enough to warrant us in plotting their distributions: 



Pecten islandicus. 

 Modiolus demissus. 

 Modiolaria laevigata. 

 Nucula delphinodonta. 

 Astarte quadrans. 

 Aligena elevata. 

 Phacoides filosus. 

 Cardium ciliatum. 

 Gemma gemma. 



Tellina tenella. 

 Siliqua costata. 

 Thracia septentrionalis. 

 Periploma papyracea. 

 Saxicava arctica. 

 Cyrtodaria siliqua. 

 Pholas costata. 

 Zirphaea crispata. 

 Teredo navalis. 



Most of these species appear to be actually rare within the region. Several of them, 

 on the contrary {Modiolus demissus, Gemma gemtna. Teredo navalis) are extremely 

 abundant in their proper habitats, though rarely taken with the dredge. 



II. AMPHINEURA. 



Of the Amphineura, or chitons, only two species are found in this region. One of 

 these, Trachydermon ruber, is quite rare locally. We have met with it but twice in 

 dredging, only a single specimen having been taken on each occasion. Both were 

 found near the lower end of Buzzards Bay. This species is essentially a northern one, 

 being said to range from the Arctic Sea to New York. The other, Chcctopleura apicuiata, 

 is scattered pretty generally throughout the eastern half of Vineyard Sound and along 

 the shores of Buzzards Bay (chart 161). Its scarcity in the western portion of the Sound 

 and its apparent absence from the deeper waters of the Bay are perhaps due chiefly to 

 the character of the bottom. As is well known, the chitons adhere to solid objects, such 



