Mr. P. H. Gosse on new or little-known Marine Animals, 31 



two specimens of Hyperoodon bidensy the capture of which in 

 Portland Roads was recorded in the 'Annals of Nat. Hist.' for 

 November 1854. Four species of Cyamus are enumerated by 

 M. Milne-Edwards in his 'Hist. Nat. des Crustaces ' (iii. 113), 

 from all of which this specimen differs signally. Indeed that 

 eminent carcinologist's resume of the generic characters must be 

 modified to include this species, which yet is an indubitable 

 Cyamus, " The first pair of feet/' he observes, " are difficult to 

 perceive when we look at the animal from above ; — they are com- 

 posed of five joints, and are terminated by a minute sub-cheliform 

 hand, slightly oval. The second pair are very large, hooked, and 

 composed of only four distinct pieces." Now in this new spe- 

 cies, the first pair do not differ either in form or size from the 

 second, third, fourth or fifth pair ; the hand is as stout, as ovate, 

 and the claw as strong and as much hooked as in the second 

 pair, while this latter pair are composed of five joints as distinct 

 as in the others, and in no wise differing from them. 



Class ANNELIDA. 



Order Ch^etopoda. Fam. Nereids. 



Genus Syllis (Sav.). 



Sp. 1. S, tubifex (mihi). 



Head lobed ; post-occipital segment equal to the following ; 

 antennse moniliform ; tentacular cirri antenniform ; feet lobed, 

 armed with one pencil of hooked setse ; superior cirrus shorter 

 than the breadth of the segment, not moniliform : animal fissi- 

 parous, minute, inhabiting a membranous tube. 



Description. — Body ^rd of an inch long, dirty-white, composed 

 of about forty-five segments. 



Head small, the lobes well developed and deeply divided, 

 clothed with short hairs. Eyes large, widely diverging ; those 

 of each lateral pair about equal in size, and placed so close as to 

 be sometimes in contact. Antennse three, moniliform, clothed 

 with short bristles ; the central one nearly twice as long as the 

 others, composed of about twenty-five well-marked joints ; the 

 outer pair having about twelve each. 



Proboscis long, the outer portion about f the length of the 

 inner. Frontal margin of outer part serrated ; inner part covered 

 with small oval tubercles, set closely in quincunx, and in trans- 

 verse rows. 



Post-occipital segment not larger than the rest ; furnished 

 with two tentacular cirri on each side, of which the upper is 

 about twice as long as the lower, equalling respectively the an- 



