THE CRUSTACEA OF NEW JERSEY. 307 



Carapace covers only anterior part of thorax, both sides 

 turned down and in to apply to base of feet. Carapace becomes 

 very narrow anteriorly ending in short flattened rostrum. Ab- 

 domen slender, tapers, elongate, nearly cylindrical. Eyes large, 

 short, bases hidden below front edge of carapace. First antennae 

 inserted above second pair below eye near median line, and 

 with twb terminal flagella to each one. Second arttenn« longer, 

 basal joint with elongated laminar appendage attached, and its 

 inner edge ciliated. Two succeeding joints of peduncle slender 

 and cylindrical, and flagellum filiform. Foot-jaws of two pairs, 

 entirely pediform. First pair short, formed of three distinct 

 branches. Of latter internal pediform portion five-jointed, hairy 

 and doubled upon itself in front of mouth. Middle branch or 

 palp elongated and formled of numerous articulations. Basilar 

 joint very large, with ciliated strap-shaped process on each side. 

 Third or external branch, or flabelliform appendage, represented 

 by semimembranous scale directed upwards and lying under 

 edge of carapace. Second pair of foot- jaws of similar forma- 

 tion, but without flabelliform appendage. Feet in six pairs, 

 formed of corresponding elements with external pedipalps and 

 five pairs of feet, as in Decapods. Each consists of two branches, 

 decreasing in length from before backwards, and fomied for 

 swimming. First four pairs of feet without flabelliform ap- 

 pendage, though last two have it. This part very small in male, 

 though greatly developed in female, and forms on each side 

 broad plate bent under sternumi, thus forming pouch in which 

 eggs are first deposited and in which secluded young pass early 

 period of their life. 



Species rather numerous, though but one recorded from our 

 shores. 



Mysis americana S. I. Smith. 



Mysis americana S. I. Smith, Rep. U. S. P. Com., I, 1871-72 (1873), p. 552. 



Beesley's Point, Neiu Jersey. Nezv Haven, Connecticut. In 25 fathoms 



off Vineyard Sound. 

 (S. I. Smith) Verrill, Rep. U. S. F. Com., I, 1871-72 (1873), p. 396, 



among algae; p. 519 (in Paralichthys dentatus) ; p. 520 (in Alosa sapi- 



dissima and Lophopsetta maculata, all from Great Egg Harbor Bay, New 



Jersey). 



