150 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



and 6 from 72 feet. Single specimens were taken at 246, 341, and 741 

 feet, and 2 specimens at 477 feet. (The last 2 stations were char- 

 acterized by muddy bottom, as were the ones at less than 125 feet.) 

 By means of dogteam dredging during the winter of 1950, 6 specimens 

 were taken at 149 feet and 7 at 162 feet, where they had been "trans- 

 planted" by the storms of autumn. Six other stations yielded from 

 2 to 4 specimens each. 



The majority of the specimens were over 10 mm. in length, the 

 longest measuring 15.5 mm., the smallest about 6.7 mm. 



Other material examined: Numerous specimens from the 

 Alaskan Arctic, Siberia, the Aleutians, southern California, and Japan; 

 Massachusetts, Greenland, the British Isles, Norway, and Spitzbergen. 



Discussion : In the Point Barrow specimens there is marked varia- 

 tion in the degree of obeseness and some variation in the proportion 

 of length to height. None of the specimens is exceedingly thin, but 

 they undoubtedly all belong to the typical form and the var. expansa 

 Reeve, with transitional forms. 



In the specimens from Point Barrow the yearly growth lines (pi. 18, 

 fig. 4) are often prominent and individuals from 11 to 14 mm. in length 

 aopear to be about 3.5, possibly 4.0, years old. 



Distribution: Nucula tenuis is known from the western Arctic 

 south to southern California, from the eastern Arctic south to North 

 Carolina, and from north of Europe south to the Mediterranean. 



Family Nuculanidae 

 Genus Nuculana Link, 1807 



Nuculana niinuta (Fabricius, 1776) 



Plate 18, figure 3 



Area minuta Fabricius, 1776, p. 414. 



Leda minuta G. Sars, 1878, p. 36, pi. 5, figs. 2a-b.— Oldroyd, 1924, p. 15, pi. 19, 



figs. 2, 2a. 

 Nuculana minuta Morris, 1952, p. 8, pi. 1, fig. 12. 



Thirty-one living specimens were taken from 17 stations ranging in 

 depth from 70 to 741 feet. Five specimens came from 741 feet, 4 

 from 477 feet, and 3 each from 295, 341, and 420 feet. The smallest 

 specimen (from 741 feet) is 6.5 mm. in length; the largest (from 522 

 feet) is 16.5 mm. in length by 8.5 mm. in height by 5.7 mm. in breadth; 

 the next largest (from 175 feet) is 15.6 by 8.4 by 5.3 mm. 



Other material examined : Several specimens in the collection of 

 the U. S. National Museum. 



Discussion: I am mdebted to W. K. Ockelmann of Copenhagen for 

 identifying this species. The specimens from Point Barrow are less 

 inflated and have a relatively longer rostrum than the specimens of 



