1818.] CRUSTACEA OF THE UNITED STATES. 247 



above the lateral thoracic spine, and disappear behind the 

 middle of the thorax on each side, a third line originates 

 from the fissure in the external canthus, passes beneath the 

 lateral spine and forms, with the two preceding lines, the 

 letter N; rostrum shorter than the eyes, obtuse, margin 

 elevated; eyes little promiiient; first joint of the peduncle 

 of the interior antennae, concave above for the repose of 

 the eyes, furnished on the external side with a submucro- 

 nate small scale, resembling an elongated continuation of 

 the inferior margin of the orbit of the eye, and armed be- 

 neath with an obtuse spine which is visible on dissebtion; 

 exterior ante w« as long as the body, annulate with black- 

 ish-brown, scales nearly as long as the interior antennae; 

 spine of the anterior feet situate near the middle of the 

 third joint beneath; ^n^^r spiniform, prominent, inflected; 

 middle process of the tail simple, conic; colour, when re- 

 cent, pale cinereous, with very numerous, irregular, stel- 

 late, blackish-brown spots. 



Length of the body, from the tip of the rostrum to 

 that of the tail, one inch and two fifths nearly. 



An active little animal; when at rest at the bottom of 

 the water it is not readily discoverable, owing to its being 

 somewhat translucent and of a pale colour. This species, 

 and those of the genus Palsemon, &c. are indiscriminately 

 called Shrimps in this country. There is no doubt but 

 our Crangon septemspinosus strongly resembles the C. 

 vulgaris of Europe, which is the true shrimp; I have, in 

 fact, considered it heretofore as the same, but it appears 

 to differ in the number of spines. — It is found as far south 

 as East Florida. 



