DECAPODS 73 
Male.—As compared with the female, the teeth of the median carina 
and rostrum are much smaller and more appressed, sometimes obsoles- 
cent, the rostrum less deep and more horizontal; the antennular acicle 
does not reach the end of the second segment of ——* 
the peduncle; the spine of the antennal scale falls x 
short of the end of the blade. 
Dimensions. — 2 , length (approximate) 38 mm., =~ 
length of carapace and rostrum 13.6 mm., of ros- 7) 
trum 6 mm. ° 
Distribution.— Arctic Alaska, Aleutian Islands pig a7 spivontocaris dallé 
to Sitka. (Xx 22). Attu. 
: P a. Side of carapace of 8. 
Although this species appears to be not rare 4. Side of carapace of ¢. 
in Alaska, it has been collected almost exclusively by Dr. Dall, who ob- 
tained it at 17 stations along the Aleutian Islands and eastward to Port 
Etches, 6-20 fathoms; off Cape Sabine, 13 fathoms; and 15 miles off 
Cape Krusenstern, 14 fathoms. 
Sitka, 2 specimens (Harriman Expedition, W. R. Coe, collector). 
SPIRONTOCARIS POLARIS (Sabine). 
Alpheus polaris SABINE, Supplement to Appendix of Parry’s [First] Voyage, 
p- ccxxxviii, pl. 11, figs. 5-8, 1824. 
flippolite borealis JAMES C. Ross, in John Ross, Appendix to Narrative of 
Second Voyage in Search of a North-West Passage, p. Ixxxiv, pl. B, fig. 
3, 1835 (2). 
Lippolite Sr JAMES C. Ross, of. ci?., p. Ixxxv (9 ). 
fTippolyte St. Pauli BRANDT, Middendorff’s Reise Sibir., Band 11, Zool., 
Theil 1, Krebse, p. 118, pl. v, fig. 19, 1851. 
fHTippolyte cultellata NORMAN, Rept. Brit. Assoc. Adv. Sci., 1866, p. 200 
(1867) (= H. polaris, teste Norman, Museum Normanianum, II, Crus- 
tacea, p. 8, 1886). 
LfTippolyte polaris SMITH, Trans. Conn. Acad. Arts Sci., v, p. 80, pl. XI, figs. 
I-4, 1879. 
fTippolyte Amazo PFEFFER, Jahrb. Hamburg. Wiss. Anst., III, 46, plate, 
figs. 7a, 7b, 1886. 
fTletairus gaimardti BATE, Challenger Rept., Zool., XXIV, 611, pl. CIX, fig. 
2, 1888 (not Hippolyte gaimardii Milne Edwards). 
Fletatrus tenuis BATE, of. cit., 613, pl. CIX, fig. 3. 
fTetairus debilis BATE, op cit., 615, pl. CIX, fig. 4. 
Professor Smith (/oc. cit.) sets forth the variations in the sexes, in the 
number of rostral spines, and in the aculei on the telson. He states that 
“the disappearance of the dorsal teeth of the rostrum is evidently a 
character peculiar to, but not characteristic of, the adult male.” In the 
series of specimens from the North Pacific and Bering Sea this is not 
the case, as the majority of the females from those localities are devoid 
of superior rostral teeth. This series also exhibits other variations. The 
body and thoracic feet are usually stouter, the antennal scale shorter and 
