ACADEMY OF SCIENCES. 35 



Alpheus equidactylus. 



A single dried specimen, broken, from Monterey, is all that we possess of 

 this very distinct species. The larger hand has a transverse sulcus imme- 

 diately posterior to the finger, and the movable and fixed fingers are of equal 

 length and extended in the same place with the hand. The rostrum is 

 narrow and sharp. 



Length, 0.75 inch. The fingers of the chelae shut close together when the 

 hand is closed. 



Betceus longidactylus. 



Form much more compressed than in alpheus bellimanus ; hands similar in 

 form; long and compressed; the fixed finger half the length of the hand, the 

 movable one more than half that length; the fingers when closed gape widely; 

 both are pointed at the end, and the points cross each other like the mandi- 

 bles of a Loxia. At the origin of the movable finger an; several teeth, opposed 

 to two large ones upon the haud itself, which also bears a large tooth in the 

 centre of the length of the fixed finger. 



Color of carapace of dried specimen, green, with nuances of russet and 

 olive. The finuers of the larger hand are light red, the tips green. 



Length of carapace, 1.12 inch; of larger hand, 0.56 inch; of smaller, 0.36 in. 



A single specimen from San Diego, on a saudy mud flat, between tides. 



Hippolyte ? Hemphillii . 



I give this provisional name to a single specimen (dried), brought from 

 San Diego by Henry Hemphill. Several of the feet are wanting, and the 

 specimen is distorted so as to render a detailed description impossible. The 

 rostrum is short and has four teeth, besides the long terminal tooth. The 

 limbs are handed transversely with alternate dark and light tints. 



Length, 1 inch. 



Hippolyte lineata. 



Rostrum less than half the length of the carapace, armed with seven teeth 

 on the upper side (including the terminal one), and three on the lower; the 

 two hinder teeth only are on the carapace, and are longer, but not higher than 

 the others; outer maxillipeds reaching to the tip of the movable scale of outer 

 antenna?; hands of first pair small and slender. The most noticeable charac- 

 teristic of this species is the presence of eight longitudinal lines of a tint 

 lighter than the ground color of the body. Upon the carapace these eight 

 lines become broken up, and mingled with other markings, producing a pattern 

 resembling that of watered silk. Two dried specimens from San Diego, 

 collected between tides, and one larger one, in alcohol, presented by Henry 

 Edwards. 



Length of largest specimen, from tip of rostrum to end of abdomen, 2% 

 inches. 



