]46 HISTORY OF BRITISH CRUSTACEA. 



Gen. 49. MACROMYSIS* 



Upper antennae armed with a scale. First, second, and 

 fifth segments of the abdomen bearing fins like the Mgsis, 

 third and fourth with the peduncles Particulate, and each 

 peduncle giving off two branches ; the outer branch of 

 the fourth very loug and slender, semi-articulated. 



Macromysis loxgispinosus, Goodsir. — Whole body of 

 a dark yellowish or greenish colour. Beak very short, but 

 sharp-pointed ; upper antennal scale of the same length as 

 the last joint of the peduncle ; lower antennal scale twice as 

 long as the peduncle, three-quarters of an inch long. 



Firth of Forth (Goodsir). 



Macromysis brevispinosus, Goodsir. — Whole body of 

 an opaque white, with a row of black spots down the back 

 of the abdominal segments. Beak of considerable length, 

 but not sharp ; upper antennal scale not so long as the pe- 

 duncle ; lower antennal scale four or five times as long as 

 the peduncle. Length an inch. 



Firth of Forth (Goodsir) ; Bangor, County Down (W. 

 Thompson) . This species and the preceding were discovered 

 and described by Henry Goodsir, who accompanied Sir John 



* Themisto, Goodsir. — Edin. New Phil. Journ. 33. A name previously 

 employed by Gueriu Meuevilie for a genus of Crustacea. 



