

T A N A I D E A. 



797 



rent shape from the following, being narrower anteriorly. The seg- 

 ments of the abdomen are five or six in number, and often subequal, 

 yet usually the posterior is largest. The stylets are simple, and three 

 to seven-jointed. The anterior or cheliform legs are short and stout, 

 and well fitted for prehension; the fingers are short, and touch by 

 their inner sides. The second pair of legs is monodactyle, and very 

 slender. The eyes consist of but few facets ; in the T. brasiliends 

 there are only six facets, five being arranged around a central one : in 

 some instances, the eyes form a projecting protuberance at the ante- 

 rior angles of the front. The abdomen is commonly about as long 

 as the last two thoracic segments. 



Tanais (Paratanais?) brasiliensis. 



Segmentum thoracis primum anticd valde angustius, septimum sexto vel 

 quinto brevius. Abdomen oblongum, ad extremitatem apiculatum, 

 6-artieidatu?n, segmentis subcequis, ultimo non longiore quam penul- 

 timum, stylis abdomine paulo brevioribus, 6-articulatis. Pedes antici 

 crassi, manu ad basiii angustiore, carpo oblongo, recto, nudo, articido 

 precedente recto. Antennae primae paxdo rnajores, corpore quadruplo 

 breviores, secundas Q-articuIata3. 



First thoracic segment much narrowed anteriorly; seventh shorter 

 than fifth or sixth. Abdomen oblong, apiculate at apex, six-jointed, 

 segments subequal, the last not longer than the preceding, stylets 

 but little shorter than the abdomen, six-jointed. Anterior feet 

 stout ; the hand narrower at base ; carpus oblong, straight, naked ; 

 preceding joint straight. Superior antennse a little the larger, about 

 one-fourth as long as the body, inferior six-jointed. 



Plate 53, fig. 3a, animal, enlarged; b, eye; c, caudal stylet; d, 

 second antennse; e, anterior legs; /, second pair of feet; g, one of 

 three posterior pairs. 



At Rio Janeiro, on sea-shores in cavities among Serpulas. 



Length, four lines. Colour, pale greenish or yellowish green. The 

 head and first thoracic segment together have a somewhat pyriform 



200 



