tail region or abdomen. The latter is composed of several simi- 

 lar rings or segments. In the body part this ring-like structure 

 (or segmentation) is more or less obscured by the large shield- 

 like carapace, which covers the back and sides, and is continued 

 anteriorly as a long, serrated spine, the rostrum. 



When first caught the shrimp is extremely beautiful in the 

 delicacy and vividness of its coloration. The body is more or 

 less translucent, and has a delicate reddish tint, caused by nu- 

 merous small reddish spots. The tips of the walking legs, the 

 long antennae, and the swimmerets are usually extremely bril- 

 liant in their tinting. The tips of the tail-fin are usually a deep 

 phosphorescent blue, shading into dark brown or black towards 

 the base of the appendage, while the heavy fringe of long hairs 

 surrounding the blades is usually a bright red. Different in- 

 dividuals show a marked variation in the general coloration; 

 some being especially vivid, while others will be nearly color- 

 less. In general, the brilliancy seems to be affected by the re- 

 centness of the last moult, those which have just shed their skin 

 being more brightly colored than those which are on the verge 

 of moulting. 



Each segment, or ring, of the body bears a pair of appendages 

 which are variously modified to serve different functions. In 

 the anterior part of the body they serve as feelers, mouth parts, 

 and walking legs. Those on the abdomen serve as paddles in 

 swimming, and on that account are called "swimmerets." Al- 

 though the different appendages are superficially very different 

 from each other in general shape, this is the result of modifi- 

 cations to fit them for the special use, and all are built on 

 the same general plan. Some of the appendages are large and 

 conspicuous, while others are very small and require a careful 

 examination in order to make them out. It will not be neces- 

 sary for our purposes to give a detailed account of the various 

 changes which have brought about the modifications in the 

 different appendages, and reference will only be made to those 

 appendages which are of special use in reproduction. 



Attention must be called to one of the modifications of the 

 walking legs which is much used in separating this group of 

 shrimp from the others. The large figure (Plate I) of this spe- 

 cies shows that three of the walking legs have pincer-like tips, 



