1921] Schmitt: The Marine Decapod Crustacea of California 79 



Genus Betaeus Dana 



Hands inverted so that dactyls are on lower side. Eostrum wanting; front 

 not spined, either emarginate between the eyes or evenly rounded. 



Key to the California Species op Betaeus 



I. Front emarginate between the eyes. Hands subequal, oval; fingers with but 

 slight gape. (From Point Arena to Laguna Beach.) 



harfordi, p. 79. 



II. Front rounded. Hands similar, long and narrow; fingers with a more or less 

 wide gape. (Not known north of San Pedro.) 



longidactylus, p. 80. 



Betaeus harfordi (Kingsley) 



Alpheus liarfordi Kingsley, Bull. TJ. S. Geol. Surv., 4, 198, 1878; Bull. 



Essex. Inst, 14, 124, pi. 2, fig. 4, 1883. 

 Betaeus aequalis Loekington, Ann. Mag. Nat. Hist. (5), 1, 479, 1878. 

 Alpheus aequalis Holmes, Occas. Papers Calif. Acad. Sci., 7, 189, pi. 3, 



fig. 47, 1900. 

 Betaeus harfordi Eathbun, H. A. E., 10, 108, 1904; Hilton, Jour. Ent. 



Zool., Pomona Coll., 8, 67, 1916. 



a b c 



Fig. 55. Betaeus harfordi; a, hand; b, dorsal view of anterior portion (after 

 Kingsley); c, hand (after Holmes). 



Characters. — Front emarginate between the eyes. Hands oval, vertical, smooth, 

 strongly compressed; dactyl slender, the inner margin straight or somewhat 

 concave near the base; fixed finger much wider than the dactyl, the entire inner 

 margin may be straight, or there may be a deep, rounded notch near the base ; tips 

 of the fingers curved and crossed when closed; inner margins pubescent, the rest 

 of the hand naked. Basal spine of the antennules long and slender, reaching 

 beyond middle of the second joint of peduncle, second joint about twice the length 

 of the third. 



Dimensions. — Types: length 19 and 24 mm., length of carapace 6 and 8 mm., 

 length of larger hand 6 and 8 mm., respectively. 



Color. — When fresh dark purple, in alcohol a light flesh tint (Loekington). 

 Pale olive green, eggs translucent green (Hilton). 



Type Locality. — Santa Cataiina Island, California. 



Distribution. — Point Arena to Laguna Beach, California. 



Bemarks. — This species lives under the mantle of Haliotis rufescens Swains. 

 (Loekington). "...but it is not confined to that habitat, for I found several 

 specimens upon sea-urchins that were brought up from several feet of water at 

 Cataiina Island. Their color was a dark purple like the specimens described by 



