178 TJnivcrsUij of Califoniia Publicatidiis in Zoology [Vol. 11 



from near the middle of each margin the spines increase conspic- 

 uously in length backwards, and the intervals are occupied by 

 quite small spines, one or two in the first interval, four spines in 

 most of the other intervals, while no small spines are found 

 between the larger ones along the proximal half of the lateral 

 margins. The telson is subtruncate with four terminal spines; 

 those of the median pair are very large, while those of the outer 

 pair are less than half as long. 



Length of the specimen seen. 8 millimeters. 



3. Neomysis franciscorum Holmes 

 PI. 9, figs. 3a, b 



The single mutilated type-specimen is at hand. Holmes 

 (1900) said: "This species is closely allied to Xeotnysis raijii 

 (Murdoch) from Point Barrow, but differs in having the telson 

 acute instead of 'truncated', and in having the terminal portions 

 of the thoracic legs divided into a greater number of articula- 

 tions. ' ' Whether the last named feature is of real value as a 

 specific character I am not prepared to decide, but Holmes's 

 statement that the telson is acute in X. franciscorum is incorrect. 

 In order to make X . franciscorum recognizable I have drawn two 

 fig^ires (pi. 9, figs. 3a, h). The species is very closely allied to 

 X. rayii Murdoch, of which I have two co-types (received from 

 the United States National Museum) and a large number from 

 various localities in northeastern Asia. 



The antennal squamae are long and very narrow in both 

 species, but both squamae of X. franciscorum having lost the 

 distal part no possible difference between the two species in this 

 feature can be pointed out by me. The eyes and eye-stalks are 

 subsimilar in both forms, perhaps comparatively a little more 

 slender in X. rayii. The frontal plate of the carapace is in .V. 

 franciscorum (fig. 3a) considerably shorter than in X. rayii; in 

 N. franciscorum it is considerably less than half as long as broad, 

 while in X. rayii it is longer and proportionately narrower, being 

 distinctly more than half as long as broad. The telson (fig. 36) 

 is proportionately narrower than in X. vulgaris, being somewhat 

 more than two and a half times as long as broad, but otherwise, 

 in the main, as in the last named species. Each margin has 



