-jq-jq CRUSTACEA. 



being fitted to fill (on closing up) only the space behind left by the 



clypeate coxse. 



There are two masses of pigment, which are of moderate size. The 

 thorax is distinctly seven-jointed. The last abdominal segment 

 carries the posterior stylets upon its under surface, as in the preceding 

 genus, and they are short. The other abdominal legs are very broad, 

 and the two branches are broad ovate. 



When the animal is closed up, it has the appearance of a short 

 bean. A large cavity is contained over the venter, which is filled 

 with water, and serves to sustain the animal a long time when out of 

 its element. 



DlTHYRUS FABA. 



Caput transversum, tumidum, fronte rotundatum, pigmentis duobus, non 

 grandibus. Antennce 2dce tenues, rectw, ^-articulator, articulo irno 

 longiore, articulis 2do Stioque subcequis, quarto breviore. Coxa quinta 

 apice valde obliqud truncata, acuta, margine postico arcuato; sexta 

 duplo majore, lunato-ovata, apice obtusa, margine jwstico omnino ar- 

 cuato, et antico oeque excavato; septima parvula, tenuis, subensiformw. 

 Segmentum abdominis ultimum triangulatum, lateribus prope apwem 

 obsolete excavatum, apice subacuto. Styli postici inferiores, ramis valde 

 incequis, basi non longioribus. 



Head transverse, tumid, rounded in front, pigments two, not large. 

 Posterior antenna slender, straight, four-jointed, first joint longest, 

 second and third about equal, fourth shortest. Coxa of fifth pair 

 with a very oblique truncation of extremity, and apex acute, poste- 

 rior margin arcuate; of sixth pair twice larger, obtuse at apex, 

 ovato-lunate, posterior margin arcuate throughout, and anterior 

 equally excavate; of seventh pair small and slender, subensiform. 

 Last segment of abdomen triangular, sides towards apex obsoletely 

 excavate, apex subacute. Posterior stylets articulated with under 

 surface of segment, branches very unequal, not longer than base. 



Plate 69, fig. 3 a, oblique dorsal view of animal, closed up; b, ven- 

 tral view, abdomen thrown back ; c, ventral view of thorax (part ot 

 organs omitted), and showing three posterior coxa of one side thrown 



