62 AUSTRALASIAN ANTARCTIC EXPEDITION. 



parapods, extending over the anterior third and over the hinder third of the body. 

 Whether these are post-mortem or not I cannot say. The head and posterior end as 

 well as the middle third are quite pale. 



There is no trace of a " tail." 



The prostomial cornua (fig. 64) are carried on a very short, wide base. The 

 anterior margin has no median notch, and the frilled membrane is continuous from side 

 to side. The extremities of the cornua are gently curved backwards, and reach to the 

 outer ends of the enlarged bases of the long cirri. 



The ciliated epaulettes are very distinct, narrow, slightly curved, with the 

 convexity mediad. They commence at the anterior margin and reach about halfway 

 along the dorsal surface of the head, terminating in a depression of its surface. In a 

 less well-preserved specimen the epaulettes assume a more or less triangular form, with 

 the base external and one angle mediad, that of the left side especially resembles Quatre- 

 fages' figure (pi. XX, fig. 1). 



The dorsal surface of the prostomium that is, the middle region of the " head " 

 is convex, and rather browner than the neighbouring region of the body; it is bounded 

 laterally by a pair of deep, longitudinal depressions, which separate it from the cirrus 

 bases on either side. 



No eyes are visible in this individual; but they are present in the smallest 

 specimen, which was stained and mounted in balsam. 



There is no sign of the " first cirrus " which occurs in some species. 



The " second cirrus " is at least 18 mm. in length, and reaches to at least the 

 15th segment. It is very delicate, breaks easily on being manipulated. The cellular 

 envelope is missing in the distal portion, and the protruding, very transparent chitinous 

 axis is difficult to trace under a dissecting microscope. It is thus difficult to state 

 exactly the length of this cirrus. But in the larger of the less well-preserved specimens 

 the cirrus is seen to extend to the hinder end of the body; so that this may, I think^ 

 be regarded as its normal length. The base of the cirrus is nearly hemispherical, with 

 a somewhat pointed apex externally, whence the cirrus arises. The longitudinal 

 diameter of the base is about equal to its transverse, and this is greater than the 

 width of the prostomium. The diameter of the " head " across the cirrus bases is 5-5 

 mm. 



Between the base of the cirrus and the first pair of parapods the gap is longer 

 than that separating the subsequent feet. The length of this gap or " neck " is equal 

 to the diameter of the body at this point. 



The distance separating the successive parapods is about half the basal length, 

 but in the poorly-preserved specimen the feet are closer together. 



At their greatest development the length of a parapod is greater than the width 

 of the body, but at either end of the series this difference decreases. 



