140 TANAIDJE. 



extremities of all the joints furnished with a few hairs. 

 The lower antennae are four (? five) jointed and slender. 

 The second pair of legs are slender, and longer than the 

 following pair, with the terminal finger long, very 

 slender, and slightly bent. The third and fourth pair of 

 legs are very short, and the three posterior pairs longer 

 and stronger. The tail nearly occupies one- third of the 

 whole length of the animal, the six segments of which it 

 is composed being distinct ; the five basal ones trans- 

 verse, and the terminal one rounded at the extremity, 

 which is furnished with a pair of biramose biarticulated 

 filiform appendages, slightly hairy at the extremity of 

 the joints. 



The first specimen of this species that we obtained 

 we dredged in Plymouth Sound. It was very small, and 

 possessed but six segments to the pereion, and conse- 

 quently wanted one pair of legs. We therefore as- 

 sumed it to have been that of a very young animal. 

 We have since, from our valued correspondent Mr. 

 Edward, of Banff, obtained two others of larger size, 

 and with the normal complement of limbs, all the other 

 features being persistent, a circumstance that induces us 

 to believe that our description represents the character of 

 an adult animal. 



We are compelled to adopt this conclusion, from its 

 difference from Tanais, its nearest ally, both in the form 

 of the second pair of gnathopoda, the number of 

 pleopoda developed as swimming appendages, and the 

 biramose condition of the posterior pair of pleopoda. 



