IS17.] GENUS PLAGUSIA. XQl 



with an elevated margin, longitudinal impressed line on the 

 middle, and two small tubercles above; lateral division)^ 

 less than half as large as the preceding, margin suddenly- 

 raised behind the exterior antenuce: exterior antennce with 

 the first joint dilated before near the tip; three serrate teeth 

 each side of the thorax, hind one smallest and placed about 

 the middle, second and third equidistant and proportion- 

 ally larger, the posterior canthus of the eye elevated into a 

 tooth, with a small tubercle within its base; coxce with two 

 elevated, somewhat comose^ scales, of which the anterior one 

 ig acute, obsolete on the four anterior feet, and the posterior 

 one obtuse; carpus with a depressed spine within, which is 

 cmarginate at tip, above with distant, small tubercles, and 

 a double, darker, impressed, submarginal line above, inter^ 

 rupted behind; hands granulate, above with small tuber- 

 cles, and two impressed Xvao.'^ fingers deflected, with obtuse 

 teeth, tip flattened and brown within; remaining feet with 

 two ciliate lines, second joint of the tibia with three; tarsi 

 with but one ciliate line, and a doable line of moveable 

 spines beneath; tip of the preceding joint about five-spined 

 beneath; spine, near the tip of the thighs, large; colour va« 

 riegated, tibia darker, spotted; beneath white immaculate. 



The very peculiar situation of the intermediate antenna, 

 in longitudinal recipient grooves, together with the closed 

 mouth, Etc., certainly justifies the separation of this, and 

 its neighbouring species, from the genus to which it has 

 hitherto been referred. I have here described it, that it 

 may be compared with its analogue of the Mediterranean, 

 which is most probably distinct. 



Taken in the Gulf- Stream, and presented by Captain 

 Bartling. 



(To be continued.) 



