NO. 6.] ACCOUNT OF THE SPECIES. 91 



fectly defined from the basal part. The 2nd joint is much the largest, 

 exceeding in length the succeeding joints combined, and carries 2 setae 

 inside, one rather short, somewhat beyond the middle, and another much 

 longer, at the end. The 2 very short succeeding joints carry each a seta, 

 but that issuing from the outer joint is so very small, that it may easily 

 escape attention. From the tip of the last joint, 3 exceedingly long and 

 slender seta? originate. 



The mandibles (fig. 4) are very small, and have the masticatory part 

 narrowly produced, almost cylindric in form, and much longer than the other 

 part. The cutting teeth are only 3 in number, the outermost tooth being 

 the largest, and somewhat remote from the other 2. The palp is more rudi- 

 mentary than in any other known Calanoid, consisting only of a simple 

 cylindric joint tipped with 2 unequal setae, and scarcely more than half the 

 length of the body of the mandible. 



The maxillae (fig. 5) are likewise very much reduced, and rather unlike 

 those in other Calanoids, each forming a simple narrow lamella, projecting 

 on each side in a small setiferous lobe. The inner of these, which occurs 

 close to the base, may answer to the masticatory lobe. It is very small, 

 knob-like, and carries 2 unequal setae of inconsiderable size. The outer 

 lobe, which issues rather more distally, seems to represent the vibratory 

 lamella. It is likewise very small, but carries 2 very strong setae, the inner 

 of which is prolonged to quite an extraordinary degree, being more than 3 times 

 as long as the whole maxilla. The distal part, which answers to the palp, 

 is narrow cylindric in form, and carries on the tip 2 strong setae of equal 

 length. 



The anterior maxillipeds (fig. 6) are well developed, though not nearly 

 so powerful as in Heterochceta, each forming a very slightly curved stem, 

 divided into 5 joints, the 2 proximal ones being much the largest, and 

 together representing the basal part. The 5 digitiform lobes of the anterior 

 edge are comparatively small, and are distinctly separated from each other, the 

 2 proximal and the distal one each carrying a single coarsely ciliated seta, 

 whereas the other 2 have each 2 such seta?. The setae issuing from the 3 

 small terminal joints are rather slender and elongated, and, when examined 

 under a very high magnifying power, are found to be thickly fringed along 



