

710 CRUSTACEA. 



The single species of this genus discovered, has an angular outline 

 to its segments, and a row of small tubercles along the back. The 

 club-shaped outer antennas are geniculate at the antepenult articula- 

 tion ; the last joint is clavate and pubescent. The inner pair is not 

 one-third as long as the outer. The thorax has seven segments ; the 

 abdomen only one. The legs are similar and subequal, and all in 

 their natural position were spread more or less laterally, as in the 

 true Idotaeae. 



This genus is named in honour of Erichson, successor of Wiegman 

 as editor of the Archiv fur Naturgeschichte. 



It is near Edotia of Gu&rin; but in that genus, the inner and 

 outer antennae differ but little in length, and the outer have a flagel- 

 lum of three or four joints. 



Erichsonia angulata. 



Elongato-ettiptica, fronte excavato, capite et segmentis thoracis angulatis, 

 transversis. Segmenta thoracis quatuor antica medio tuberculum 

 gerentia. Abdomen uni-articulatum, oblongum, subscutellatum, ad 

 latera sinuosum, versus apicem latins, extr&mitate triangulatum, ob- 

 tusum. Antenna? internal fere quadruplo breviores, 4:-articidatce ; 

 external dimidio corporis longiores, Q-articulatai, articulis tribus ultimis 

 subcequis, penultimo hreviore, ultimo obtuso, breviter liirsuto. Pedes 

 suba3qui, duobus posticw et anticis brevioribus ; articulo basali crasso, 

 plerumque tuberculato. 



Long elliptic, front excavate, head and thoracic segments angulate, 

 transverse ; four anterior segments of thorax with a tubercle at 

 middle. Abdomen one-jointed, oblong, subscutellate, margin sinu- 

 ous, broadest near apex, extremity triangulate, obtuse. Inner 

 antennae nearly four times the shorter, four-jointed. Outer longer 

 than half the body, six-jointed, last three joints subequal, the penult 

 shortest, the last obtuse and short hirsute. Feet subequal, two 

 posterior and two anterior shortest; basal joint stout and generally 

 tuberculate. 



Plate 46, fig. 10, animal, enlarged. 



