Cape Hatteras 



34 N 



I ' •- 



KM. 50 



78° 77" 76" 75"W 



Figure 3. — Stations in North Carolina at which seven of the nine "northern" asteroids have been taken. 



Current or in deeper waters near and off the edge 

 of the shelf. On tlie other liand, "southern" spe- 

 cies — those that are distributed from North 

 Carolina southward — rarely are taken in stations 

 north of Cape Hatteras except near the edge of the 

 shelf under the Florida CuiTent. 



A greater number of species, but smaller popula- 

 tions, occur along the outer shelf (110-200 m.), 



whether in the Caribbean Province or north of 

 it, than in either the Virginian or Carolinian Prov- 

 ince. Either or both of two factors not easily sep- 

 arated may account for this distribution : depth 

 and more uniform temperature. Tlie range of bot- 

 tom temperatures of the outer shelf is far less than 

 that of either the middle or imier shelf. North of 

 lat. 35°30' N., northern and southern species ap- 



132 



U.S. FISH AND WILDLIFE SERVICE 



