166 Bulletin, Vanderhilt Marine Museum, Vol. Ill 



which are slender, subequal, with the tips slightly down-curved, meet- 

 ing, with many setae in the hiatus. 



The second legs are • exceedingly slender, with the carpus multiar- 

 ticulate, the first article twice the length of the second equal to the 

 third and fourth taken together, which are subequal ; the fifth article 

 about one and three-fifths times as long as the fourth ; the dactyl has 

 the palm about as long as the preceding article but stouter, the fingers 

 nearly twice as long as the palm, laterally compressed and set with 

 tufts of bristling setae. 



The third, fourth and fifth legs are similar, monodactyl, decreasing 

 slightly in length in the order named. The merus of each is the long- 

 est and widest joint of the series ; the carpus is slenderer, three-fifths 

 as long as the merus and subequal in length to the propodus, which is 

 set with a series of spines along the inferior lateral margin ; the dactyl 

 is short, curved, acuminate. 



Alpheus formosus Gibbes. 



Plate 59. 



Type : Taken at Key West and deposited in the Philadelphia Acad- 

 emy of Natural Sciences. 



Distribution : A reef-dweller, known from Key West, Florida, the 

 Bermudas, Porto Rico, Cuba, Barbados and the coast of Brazil, as far 

 down as Pemambuco. 



Material examined : One specimen taken at Pigeon Key, Florida, 

 February 17, 1923, by the ''Ara/' William K. Vanderbilt, com- 

 manding. 



Color : In life this species is one of the most vividly and character- 

 istically colored of the sponge-dwelling shrimp. The ground-color of 

 the body is yellowish or olivaceous green, finely speckled with bright 

 orange, with a median dorsal and two lateral stripes of orange, pale 

 yellow or white, and the abdominal margins vivid blue. The caudal 

 fan is creamy proximally, margined distally with orange. The large 

 claws are of the same yellowish or olivaceous green as the body, with 

 the base of the lower finger white, the tips of both fingers are bright 

 orange. The antennal and antennular flagella and ambulatory legs 

 are vivid blue. 



Technical description : Animal moderately robust, with the great 

 chela elongate-oval, swollen proximally, less so distally, devoid of 

 notches, somewhat resembling the claw of typical Synalpheus. Ros- 

 trum a prominent, narrow, elongated triangle, well defined proximally, 

 the distal three-fifths acuminate, extending beyond the frontal margin 



