238 GAMMAKID.E. 



mal is smooth. The tail has the four anterior segments 

 with the dorsal margin in each posteriorly produced and 

 elevated into a strong tooth ; the fourth is also marked 

 by a dorsal sinus. The eyes are oblong. The antennae 

 are subequal, slender, the superior having the two joints 

 of the peduncle of nearly the same length, the first joint 

 being furnished, at the infero-distal extremity, with a 

 blunt tooth. The inferior antennas are a little shorter 

 than the superior, and have the penultimate joint of the 

 peduncle pubescent upon the upper surface. The first 

 two pairs of legs are slender, and not very strong ; the 

 hands having the palms oblique, and minutely pectinated, 

 the anterior being the more coarsely marked. The next 

 two pairs of legs are very slender and feeble, but the 

 last three are somewhat more robust, and generally carry 

 the fingers directed backwards. The caudal appendages 

 reach nearly to the same length, and have their branches 

 equal. In Montagu's type specimen in the British Mu- 

 seum the middle pair of appendages are rather shorter 

 than the others. The terminal plate is very long, and 

 split to about two-thirds of its length ; the margins are 

 fringed with a few hairs, and the apex armed with a 

 single spine on each side of the central division. 



This very pretty species, which for a long time ap- 

 peared to find no generic resting-place, was first figured 

 and described by Montagu, but his description was so 

 short, and his figure so imperfect, that Prof. Milne- 

 Edwards was unable to identify it with the species that 

 he described and figured under the name of Amphitoe 

 Marionis, Like Montagu, Milne -Edwards figured his 

 species from a specimen which had been deprived of the 

 central tail-piece, which articulates so delicately in this 

 species, that it is very commonly absent even in recently- 

 dredged animals. Montagu's specimen is preserved in 



