SHRIMPS OF THE GENUS BETAEUS — HART 441 



is difficult because of its protective coloration and transparency. The 

 shrimp is so striking in appearance, however — with its large chelipeds 

 and lobster-like form — that specimens found incidentally when other 

 animals are being collected are not likely to be discarded. Yet there 

 are very few preserved specimens even from areas where the fauna is 

 well kno\vn. Is it, therefore, really rare or only rarely found? Dr. J. 

 S. Laurie, collecting in Oakland Bay, Puget Sound, seems to be the 

 sole person to have obtained the shrimps in any number, and this 

 was done only over a period of more than one year. Subsequent 

 searching by other workers in the same area has not been productive. 



Rathburn (1904) described Betaeus harrimani from a single female 

 found at Sitka, Alaska. With the exception of Banner's comment 

 (1953) on the far northern habitat, I am unaware of any other ref- 

 erence to the species in the literature. The present specimens agi"ee 

 with Rathbun's description except in a few minor details. The palm 

 of the second leg seems to be appreciably longer than the fingers, not 

 subequal as she stated, and the posterolateral angles of the fourth and 

 fifth abdominal plem'al segments are square, rather than rounded. 

 The proportionate length and width of the palm, the presence of large 

 teeth on the fingers, and the gape differ radically from the finely 

 denticulated, nongaping type she described. There is little doubt 

 that all specimens in the present collections are B. harrimani because, 

 although in many specimens both chelae are very different, others 

 have one chela denticulate and nongaping and the other chela toothed 

 and gaping. 



Ovigerous females have been found in the field June-September and 

 in the laboratory December-July. The eggs are a bright green when 

 fii'st extruded but become brownish and more transparent before 

 hatching. 



Betaeus longidactylus Lockington 



Figures 20-22, 27, 32-34, 40-42 



Betaeus longidactylus Lockington, 1877a, p. 35 (type locality, San Diego, Cali- 

 fornia; holotype not extant); 1878, p. 480. — Rathbun, 1904, p. 108.— 

 Baker, 1912, p. 106.— Hilton, 1916, p. 67.— Schmitt, 1921, p. 80, pi. 12; 

 1924, p. 387.— Johnson and Snook, 1927, p. 310, fig. 262.— MacGinitie, 1930, 

 p. 68; 1935, p. 658, 660, 686, 705-706; 1937, p. 1035.— MacGinitie and 

 MacGinitie, 1949, p. 279.— Ricketts and Calvin, 1952, p. 42, fig. 18. 



Alpheus longidactylus Kingsley, 1878a, p. 198. — Holmes 1900, p. 190. 



Female. — Carapace laterally compressed but without carina. 

 Smooth, with very fine scattered setae somewhat concentrated over 

 branchial region. Longer setae on posterior margin. Front (fig. 

 20) straight, depressed anteriorly, slightly swollen over eyes. No 

 distinct junction with lateral margin (fig. 21). Width of carapace 

 increases rapidly so that most of carapace subequal in width, but 



