EUNICE NORVEGICA. 437 



The proboscis has a strong pair of maxilla?, the curve of each of which is rather flat. 

 In lateral view the tips rise very little, so that the organs are nearly horizontal. Posteriorly 

 the outer angle of each maxilla is slightly elevated and projects as a prominent external 

 shoulder. Within this is a definite raised longitudinal ridge, which alternates with that of 

 the opposite side, so that the one fits into a pit superiorly, the other inf eriorly — thus locking 

 the jaws securely together, especially against vertical motion. Moreover, as the maxilla? fit 

 into a crescentic hollow of the great dental plate, additional security is given to the grasp of 

 food or living prey (Plate LXIII, fig. 4). Each maxilla articulates with a spatulate process 

 posteriorly. The great dental plates are powerful and each has seven teeth, the largest in 

 front. These teeth appear to have a scissor-like action, the left passing over the right. 

 Rather more than a third of the posterior edge is smooth. The first antero-lateral plate 

 on the left is further backward than that on the right, and forms what has been termed 

 an azygos plate with nine teeth. It is also less arcuate than that on the right. The 

 curved plate next it has six teeth, and there are two brown denticles — a larger and a 

 smaller — which continue the row, and each has a terminal denticle. The right anterior 

 curved plate has ten or more small teeth, and a larger and a smaller denticle continue the 

 series beyond it, as on the opposite side. On the ventral surface a slender horny bar 

 occurs on each side between the curved plates and the great dental, but it is disconnected, 

 and there is no horny bar going to the maxilla? as in other forms. 



The mandibles (PI. LXIII, fig. 4 a) are powerful, the anterior oblique edge being 

 denticulated, and the oral plate (which, as usual, is most extensive ventrally) is white. 

 The posterior limbs taper to a blunt point. They are brownish-grey with a darker 

 internal edge. Slight movement occurs between the halves of the apparatus. 



The branchia? commence as a short subulate process attached as a rule to the inner 

 base of the dorsal cirrus of the fourth foot, though it may be the fifth in some — indeed, there 

 is variation in this respect. About the eighth foot the branchia has three divisions and 

 the same on the right tenth foot, the left having only two. The eleventh has three on 

 one side and two on the other, whilst the twelfth has two on each side, but the right 

 dorsal cirrus is bifid. The branchise behind generally have two divisions, occasionally 

 three, then they diminish to one and cease at the fortieth foot, or occasionally there are 

 rudimentary or simple processes to the forty-third or forty-fourth. The highest number 

 of branchial filaments in each foot is four. In some young examples the highest is three. 

 0. F. Muller describes his E. pinnata as having branchia? from the seventh to the fortieth 

 foot, and the pinna? varying from six to eleven. Various abnormalities occur from injury 

 and partial reproduction. 



All the parts of the foot undergo diminution at the fortieth, only a minute branchial 

 process being present on the base of the cirrus. The ventral cirrus is also less. The 

 spines are either black, or, in young forms, of varying degrees of yellow or brown. As a 

 rule they are gently tapered almost from the base to the tip, which is very slightly hooked 

 — that is, curved backward and then forward. The tips are often abraded. 



Posteriorly are the blackish hooks (Plate LXXXIII, fig. 9 c), the shafts of which have 

 a more decided curve than the spines, the tip being bent backward and then forward as it 

 diminishes to the neck. The great fang is short and stout, its inferior border forming 

 more than a right angle with the neck, whilst the single short spike on the crown is 



