202 
BULLETIN OF THE BUREAU OF FISHERIES 
The study of growth and maturity forms the main part of this paper. These 
matters are not only of scientific interest but are of importance on account of the 
bearing which they have on the measures of conservation that have been put into 
effect or may be recommended for the future. On this account the paper will be 
of more than usual interest to the men engaged in the clam industry of Alaska, 
and it has seemed desirable to include a discussion of certain matters which would 
not ordinarily be included in a strictly scientific paper, but which experience has 
shown will be of interest to the nonscientific reader and will lead him to a better 
understanding of the more technical portions. 
We wish to acknowledge the advice and helpful criticism of Dr. Willis H. Rich 
during the progi'ess of the work. 
THE RAZOR CLAM 
The razor clam, Siliqua patula (Dixon), occurs in commercial quantities from 
near the mouth of the Columbia River to the Aleutian Islands. Canning has been 
carried on at Warrenton, Oreg., along the whole coast of Washington, on Van- 
couver and Graham Islands in Canada, and at Cordova, in Cook Inlet, and Shelikof 
Straits, Alaska. This range possibly may be extended by the opening of canneries 
in southwestern Alaska along the Alaska Peninsula. It is essential to determine 
whether the variations encountered in this 2,800 miles of coast are of specific value. 
The razor clam {Siliqua patula) was first described by Dixon in 1788 from 
specimens found near Coal Harbor, Cook Inlet, Alaska. Conrad found shells near 
the mouth of the Columbia River in 1838, and described them as a separate 
species — Siliqua (Solen) nuttaUii. Later this was changed in rank to a variety 
of the original Siliqua patula. Other species and varieties exist, which, however, 
need not be considered here. A description of the two mentioned above, taken 
from Dall (1899, p. 109), is as follows: 
3. Siliqua patula Dixon, 1788, Okhotsk Sea ; the southern border of Bering Sea, and the 
Gulf of Alaska to Sitka. 
Described from Cook Inlet, Alaska. * * * Large, with the submedian beaks and 
straight rib. The following are discriuiinable varieties, but apparently connected by grada- 
tions with the typical S. patula. 
4. Siliqua (patula var.) alta Broderip and Sowerby, 1829; Be?'ing Sea and Strait. * * *. 
5. Siliqua (patula var.) nuttallii Conrad, 1838, Lituya Bay, Alaska, south to Oregon, and 
California as far as Monterey. 
* * *. The shell is very straight, brilliantly polished, narrower than the typical S. 
patula and with a much more oblique rib. * * * . 
A full copy of the original description is given by Oldroyd (1924, p. 58) 
without comment. The distinction given rests on the direction of the rib, which is 
said to be " straight " in " patula " and " more oblique " in " var. nuttallii,''^ and on 
the proportional width of the shell, which is alleged to be broader in '■'■patula'''' 
than in " var. nuttallii.'''' 
It is not difficult to separate Alaskan and Washington shells by their general 
appearance, but these differences are, we think, not of specific rank. The clams 
from the northern waters grow more slowly; the annual rings of growth on the 
shell, plainly visible upon even superficial examination, are thus more numerous 
