DECAPODS 117 
Bailey Harbor, Alaska Peninsula (4/batross). 
Coal Harbor, Unga Island, Shumagins, 3 fathoms (W. H. Dall). 
Also occurs along the eastern coast of North America, from East 
Florida (Say) northward. 
It becomes necessary to separate the common Cvangon of the Atlantic 
and Alaskan coasts of North America from the form found in Europe. 
These two species have usually been combined under the name Crangon 
crangon (Linneus) or C. vu/garis Fabricius. 
In Crangon crangon (of Europe) the antennal scale is wider at its 
distal end, and that margin, although convex, trends forward toward the 
inner angle. The spine is shorter than the distal width of the blade. 
In Crangon septemspinosa Say (of America) the scale is narrower at its 
distal end, and that margin, although convex, does not trend forward 
toward the inner angle, but rather slopes backward. ‘The spine is as 
long as, or longer than, the distal width of the blade. 
CRANGON ALBA Holmes. 
Crangon alba HOLMES, Occas. Papers Calif. Acad. Sci., VII, 174, 1900. 
Monterey, dredged. 
A short stout species. Carapace about two fifths as long as abdomen. 
Rostrum broader than in C. nigricauda. The first segment of the anten- 
nule exceeds the process on the outer side of its base; 
inner flagellum exceeding the antennal scale; outer ~~ 
flagellum shorter than the scale. Blade of scale with 
very oblique inner margin, the tip scarcely wider than 
the adjacent portion of the spine; spine extending . 
considerably beyond the blade. Scale « 
about three fourths the length of carapace. Fic. 6 _ Crazgon 
alba. @. San Diego. 
1 eee Maxillipeds reaching the end of the ie oie eae 
alba. Chela of ¢ blade, the antepenult segment much ex- (*?)- 
it ata panded. The first pair of feet reach to the middle of 
the last joint of the maxillipeds; the hand is very stout, wider than in 
C. nigricauda, the length being two and one fourth times the width 
measured from the inner base of the immovable spine; the anterior 
margin is more longitudinal than transverse. 
The segments of the abdomen are smoothly rounded; the sixth is 
rounded beneath, not grooved; the seventh is not sulcate above. 
Dimensions.—An ovigerous female (station 3679) measures 48 mm. 
long, carapace 12.5 mm., scale 9.7 mm. 
Distribution. —From Vancouver Island, British Columbia, to San Diego, 
California, to a depth of 47 fathoms, at the following localities: 
— 
