SHRIMPS OF THE GENUS BETAEUS — ^HART 453 



in proportion. In one specimen, left side of peduncle of uropods cut 

 into two small teeth, but right side with only one tooth. Appendix 

 masculina bristled on distal half and on tip; twice as long as appendix 

 interna and reaching midway between tip of appendix interna and 

 tip of endopodite. 



Color. — "Dark purple . . . resembled the color of the sea urchins 

 in whose spines they were entangled when captured" (Holmes, 1900). 

 "In life I have noticed no difference in the color of B. harfordi and the 

 last one we are sending you from the sea lu-chin. For the most part, 

 they are mostly blue, but sometimes along the side the color is a 

 reddish brown. The claws and tail are almost always entirely blue 

 regardless of the color along the sides of the abdomen. I could find 

 no correlation between color and sex" (Mrs. G. E. MacGinitie, 

 letter, 1958). 



Size. — Carapace length of smallest ovigerous female 6.8 mm.; 

 largest female 10.5 mm. ; males 5.5-10 mm. Length of chela of largest 

 female 10.3 mm.; of largest male 10.5 mm. 



Range.^ — Santa Catalina Island to Monterey, Calif. 



Habitat. — Occurs in pairs in association with sea urchins, 

 Strongylocentrotus franciscana (Agassiz) and S. purpuratus 

 (Stimpson) . 



Material. — -The following specimens were examined ; 



California. — Santa Catalina Island, Isthmus Harbor, Nov. 27, 1913, Anton 

 Dohrn, 1 ovigerous female (USNM 107546). — Laguna Beach, under Strongylocen- 

 trotus purpuratus (Stimpson) in hole in rock, Nov. 18, 1937, N. MacGinitie, 1 

 ovigerous female, 1 male. — Corona del Mar and Laguna Beach, shale reef mid- 

 way between, ]i mile offshore, 5 fathoms, from beneath Strongylocentrotus fran- 

 ciscana (Agassiz), Apr. 17, 1958, Robert Given, from N. MacGinitie, 1 ovigerous 

 female. — Corona del Mar, Arch Rock, tide pool (may have been with purple sea 

 urchin before being disturbed), Oct. 1932, N. MacGinitie, 1 female. — Corona del 

 Mar, off Ladder Rock, 4 fathoins. May 22, 1958, Robert Given, from N. Mac- 

 Ginitie, 1 female holotype (USNM 108228).— Monterey Bay, China Point, June 

 1908, 2 females (1 ovigerous), 1 male (Hopkins Marine Station). 



Notes. — Some specimens have the proximal part of the fingers of 

 the chelipeds denticulate rather than with a distinct tooth. Oviger- 

 ous females have been taken in April, June, October, and November. 

 Mrs. MacGinitie reports that the eggs, when freshly laid, are nearly 

 opaque and a pale yeUo wish-green, becoming more transparent with 

 development. 



Betaeus gracilis, new species 



Figures 50, 51, 66, 65-67, 77, 78 

 Betaeus harfordi Hilton, 1916, p. 67. 



Female. — Carapace laterally compressed but without carina. 

 Smooth, with scattered fine short setae. Setae on posterior margin 



