384 MYSID.E. 



STOMAPODA. MYSIDM. 



Themisto Iremspinosa. H. Goodsir. 



Specific Character. " Superior antennal scale not so long as the peduncle. In- 

 ferior antennal scale four or five times as long as the peduncle. Internal branch 

 of the third subabdominal fin minute ; the internal branch of the fourth longer 

 than the first joint of the external branch ; the external branch extending a little 

 beyond the base of the caudal fins, ending by means of a dart-like point. The 

 lateral caudal fin ending in a sharp point superiorly, and rounded inferiorly ; the 

 internal fin oblong, ovate, and pointed. The lateral edges of the middle plate 

 bearing a single row of long, sharp, and bent spines, contracted near the base 

 and the bottom of the fork, forming an acute angle ; prongs pointed. 



" Long, one inch. Hab. Frith of Forth. 



" Description. The whole body more robust than that 

 of the last-described species, and of an opake white colour, 

 with a single row of black spots along the dorsal mesial 

 line of the abdominal segments. The first joint of the 

 peduncle of the inferior antennae very short and almost 

 circular ; the two following are slender. The scale which 

 arises from the superior part of the first joint above the 

 true antenna is very strong at the base, and then tapers 

 gradually to a fine point. A fringe of long hairs borders 

 its inferior edge. These hairs are matted at the extremity 

 so as to give them the appearance of a second joint ; two 

 or three short strong spines arise from the extremity of the 



