368 THE PLANKTON OF THE FAROE CHANNEL AND SHETLANDS. 



the <? of this species is unknown), are not alike, the chewing end of one 

 carrying two trifid, one single pointed, and one long, stout, pointed outer 

 tooth (four in all), whereas the chewing end of the opposite mandible 

 carries only two slenderer, long, pointed teeth. The exopodite of the 

 mandible carries four extraordinarily long and densely feathered bristles, 

 the endopodite is well developed. The last joint of the outer branch of 

 the fourth feet is of similar form to that of the third foot. The fifth 

 feet are unlike those of any known Heterochaeta, the second basal of the 

 right foot being produced into a long comb-like process with stiff, short 

 bristles on the inner margin, the first segment of the exopodite is small, 

 the second very large and very broad with the internal margin armed 

 with two protuberances, one having a series of short teeth, the other 

 and distal one armed with a few stiff bristles. The second basal of the 

 left foot has a rounded and projecting distal inner margin armed with 

 stiff bristles. The bristles of the posterior antenna are of great length 

 and densely feathered. 



In size, length of anterior autennte, characters of the basal joint of the 

 posterior foot jaw, and of the anterior foot jaw, and normal shape of 

 the third segment of the exopodite of the fourth foot this Copepod 

 resembles H. longicornis (Giesb.). The 3^ of this species is, however, 

 unknown, and the example under notice may possibly be this, or a 

 new species. Provisionally I name it zetesios. 



Pleuromma robustum, Dalil. 



Many examples of this Copepod have been captured in my Faroe 

 tow-nettings, and I found several examples of it in Fowler's Ilesearch 

 Collection. The ? averages 4 mm. length, the <? 3'5-37 mm. The 

 pigment spot is always on the right side of the body, and the clasping 

 antenna on the left. The teeth of the anterior antenna are small, and 

 both the second feet have excavations and teeth on the first segment of 

 the internal branch. The abdomen is quite symmetrical. Dahl re- 

 marks of this species that though found in tropical areas of the ocean 

 singly and in deep water, it has a wide distribution, and in northern 

 regions comes nearer to the surface, having been once taken in the 

 vertical net from 100 metres to the surface. I have taken it several 

 times in the closing net at 100 and 150 fathoms. 



Thaumaleus longispinosus <?. 



Only the ^ of Th. lonrjispiiioms and TJi. thompsonii are known, and 

 the furca of the former has four bristles, while that of the latter species 

 has only three. If the tail bristles are to be regarded as of constant 

 diagnostic value, this specimen approaches more nearly to Th. longi- 



