THEMISTO BREVISPINOSA. 385 



scale. The third joint of the peduncle of the superior an- 

 tennae is considerably produced at its superior angle. The 

 scale which arises beneath the setaceous portions is strong, 

 bent upwards at its extremity, and pointed, but not fringed. 

 The eyes are large ; the reticulated portion circular. 



" The rostrum is of considerable length, but it is not 

 sharp. The internal branch of the third subabdominal 

 fin is minute ; the external one is long, slender, and finely 

 pointed ; it is also fringed with very long hairs. The in- 

 ternal branch of the fourth fin is longer than the first joint 

 of the external branch ; and it is both more strongly 

 ringed and more moveable than that of the last-described 

 species. The external branch extends a little beyond the 

 base of the caudal fins. The sixth or last joint of this 

 branch suddenly contracts near the extremity to about half 

 its original thickness, ending in a dart-like point. The 

 external caudal fins end in a sharp point inferiorly, and 

 are rounded inferiorly ; the internal fins are oblong, oval, 

 and pointed at the extremity. These are both fringed 

 at their inferior edges and at their extremities. The late- 

 ral edges of the middle plate armed with a single row of 

 strong hooked spines. It is contracted near the base, 

 and the angle formed by its bifurcation is very acute ; 

 the extremities of the prongs are also sharp-pointed, and 

 of a black colour." 



Amongst the numerous and interesting additions to our 

 knowledge of the smaller Crustacea, for which we are in- 

 debted to Mr. H. D. Goodsir, are the three foregoing 

 species of the family MYSID^E. As I have never seen spe- 

 cimens of either of them, I have thought it best to give, 

 verbatim, Mr. Goodsir^s own descriptions, although some- 

 what diffuse, with copies of his figures. 



c o 



