MYSIS. CRUSTACEA. 169 



lary or setaceous ; the last for swimming ; body long, soft, 

 much compressed. 



P. sivado, Desm. Body compressed, arched; shell smooth, termi- 

 nated before by a pointed rostrum ; first pair of feet spinous and 

 reddish, the others slender and hooked ; last segment of the ab- 

 domen very thin ; body soft, whitish, silvery, and the margins red. 

 2^ inches long. Mediterranean sea Risso, Crust, pi. 3, fig. 4. 



FAMILY VIII. SCHIZOPODA. 



All the feet weak, filiform, proper only for swimming, and ac- 

 companied either with a long lateral appendage, or deeply 

 bifid or multifid at their extremity, none of them terminated 

 in a hand. 



Gen. 74. MYSIS, Lat. 



Four setaceous antennae, the lateral ones longest, with a large 

 ciliated scale at the base, the intermediate bifid ; exterior feet- 

 jaws with the middle joint of the peduncle longest ; legs bifid, 

 the last of the four anterior pairs with interior laciniaovate, com- 

 pressed ; body long, cylindrical ; shell smooth ; eyes very 

 large, globular, on short and thick peduncles ; abdomen of 

 six segments, terminated by a fin of five leaflets ; females with 

 valves at the breast for the ova. 



M. spinulosns, Leach. Tail with the intermediate lamella externally 

 spinulose, the apex acutely emarginate ; exterior lamellae acumi- 

 nate and very broadly ciliated ; colour pale cinereous ; eyes black, 

 red at their base. 1^ inch long. Inhabits shores of the Frith of 

 Forth, near Edinburgh Lin. Trans, xi. 350. 



Gen. 75. NEBALIA, Leach. 



Thorax with a moveable rostrum anteriorly ; anterior pair of 

 legs longest, simple ; other pairs equal, approximate, with the 

 last joint bifid ; antennae two, inserted above the eyes, the last 

 joint bifid and multiarticulate. 



N. Herbstii, Leach. Gray or cinereous yellowish ; -eyes black. 8 

 lines long. Inhabits European seas. Lin. Trans, xi. pi. 2, fig. 5. 



Gen. 76. ZOEA, Bosc. 



Eyes two, sessile, one on each side of the head ; rostrum per- 

 pendicular, the length of the thorax ; thorax ovate ; shell dia- 

 phanous, with the back produced into a spine ; legs obscure 

 and short ; tail as long as the thorax, and composed of five 

 joints ; four antennae, almost equal. 



Z. pelagica, Bosc. Body transparent as glass ; eyes and a spot at 

 the base of the dorsal spine fine blue. J line long. Inhabits At- 

 lantic Ocean. Bosc, Crust, ii. pi. 15, fig. 3, 4. 



