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174 CALIFORNIA ACADEMY OF SCIENCES. 



there is nothing corresponding to it or approaching it 

 in any specimen of nigricauda I have seen. Both 

 species are often brought up in the same dredge load and 

 they can easily be separated at sight. The two species 

 occur side by side from northern to Lower California 

 without any notable approach to intergradation. 



Crangon alba, sp. no v. 



Closely allied to nigricauda, from which it differs in the following 

 points: The antennal acicle is more narrowed at the tip and the mem- 

 branous portion does not project forward. Hand slightlj'' wider in the 

 middle. The fifth and sixth segments of the abdomen are evenly rounded 

 above and not at all crested. The lower side of the sixth abdominal seg- 

 ment is not grooved. The telson is evenly rounded above and devoid of a 

 sulcus. 

 /\^ Color nearly white. 



Dredged at Monterey, November, 1895. Collection 

 University of California. ' 



Crangon s):ylirostris, sp. nov. 



Resembling nigricauda, witn the spines on the thorax the same in num- 

 ber and position, with the exception that there is no trace of a spine on 

 the gastric area. Body stouter than in franciscorum. The rostrum is 

 longer than in nigricauda, narrow, grooved above and tapering to a slen- 

 der, acute tip, which is curved strongly downwards and much compressed 

 laterally. The antennular peduncle does not reach so far forward as the 

 middle of the antennal scale, the process on the outer side of the basal 

 joint similar to that of nigricauda; the second joint of the peduncle is 

 broader than long and much shorter on the outer than on the inner side; 

 inner flagellum longer (but not one-half longer) than the outer, which 

 about equals or a little exceeds the tip of the acicle. Antennae shorter 

 than the body; acicle about two-thirds the length of the carapace and 

 narrow at the distal end, with the antero-internaJ angle not at all pro- 

 duced. The external maxillipeds reach nearly to the tip of the antennal 

 scale. The anterior chelipeds closely resemble those of nigricauda; a 

 spine near the middle of the under side of the merus; hand oblong, about 

 twice as long as wide, slightly widened distally, with the distal margin 

 convex and oblique; spinous poUex oblique; finger fitting closely against 

 the margin when closed. Second pair of pereopods more slender and 

 a little longer than the third; last two pairs subequal. Sternal spine well 



