OTAKI : STICKLE-BACKS OF JAPAN. Sj 



(needle-fish) and hartisaba (spring mackerel) are most probably the old dis- 

 tinguishing names for this species, for these names are casually seen in the literature 

 describing local finny creatures. The range of distribution is extensive in Japan, 

 abounding northward, and especially so in the island of Hokkaido. 



Pygosteus breznspinosiis, Otaki. n. sp. 



D. IX. II. A. I. II (9}, P. 10. 



Head 4 ; depth 5 in the length or i^ in head ; snout 4 in head. Diameter of 

 eye equals the snout or 3i times in the head ; the interorbital space equals the 

 snout : mouth oblique, the lower jaw not perpendicular as to give the chin angular 

 appearance as it is in the P. steindachneri. The maxiliaries short, barely reaching 

 the under margin of the nostril. The dorsal spines much shorter than those of the 

 former species, they are supported by a membrane ; the length of them is tvvo-thirds 

 of the diameter of the eyes, the last is curved and longer, the length equalling the 

 snout, and also the anal spine. The ventral spine long and laterally serrated, 

 with a weak soft ray following, its length equals the distance fi-om the tip of snout 

 to the anterior margin of pupil. The bases of the dorsal and anal fins equal, and 

 they are opposite each other. Body rather slender, devoid of the lateral armature 

 except those of 5 or 6 small ones forming a keel on the caudal peduncle. The 

 V entral pubic plates lanceolate, the length shorter and width narrower than those 

 of P. steindachneri, and the former is three times the latter ; the lateral pubic plate 

 shorter and cuniform. The firesh colour yellowish pale gpreen and dusk^- above, the 

 belly, chin, and ventral fins colourless, in spawning specimens the entire body, fins 

 and all, dusky or duskj"- black. 



This species is a small darting fellow living in small streams in Sapporo, 

 running from cold springs, where the bottom is fine muddy sand and fiill of swamp 

 weeds. The largest size of the specimens we hav^e taken is 5 or 5! cm long. 

 From the same stream a number of P. steindachneri were taken. 



Pygosteits nndecimalis, Jorden & Starks. 



Body elongated and thick, and completely smooth except narrow plates on the 

 caudal peduncle, forming a keel. The ventral pubic plates absent or insignificant!}' 

 small. 



D. XI. lo-ii (rarely XioiO' A. 1,9-10, P. 10. 



Head obtuse with a shortish snout ; its length 4 or scarcely 4 in the case of 

 female : depth 5 or less ; eye comparatively small, its diameter being 3I-4 in the 

 head or the same with snout. The maxiliaries barelv reach the eve. The dorsal 



