CRUSTACEA OF THE MEEaTJI AECHIPELAGO. 37 



internal hiatus of the orbits, the inferior margin of which is not 

 united with the upper margin ; the basal joint is rather small, 

 the second scarcely reaches the front, and tiie third joint occu- 

 pies the orbital hiatus, though not filling it. As in Myomenippe, 

 the flagellum of these antennae is rather short, being only as 

 long as the breadth of the front. 



The cephalothorax is rather enlarged, the proportion of its 

 length to its breadth (the distance of the penultimate antero- 

 lateral teeth) being, as Heller rightly observes, as 43 to 63. 

 The upper surface is slightly convex longitudinally, being rather 

 declivous towards the front and towards the antero-lateral 

 margins ; the posterior half is rather flattened and much de- 

 pressed. The interregional grooves are very shallow, and some 

 of them are scarcely or not at all indicated ; besides the usual 

 median frontal furrow, shallow gastro-branchial and branchio- 

 cardiac grooves are present, the latter being, however, very 

 faintly marked in young individuals. The transverse groove 

 (cervical suture), which in other species separates the gastric 

 region from the cardiac, is wanting. On each side of the 

 gastric region, a faintly marked, arcuate sutural line is found, 

 the inner end of which terminates in the middle of the gastro- 

 branchial groove ; whereas the postero-external end issues into a 

 short impressed line, which proceeds obliquely inward and back- 

 ward from the last antero-lateral tooth. The same grooves are 

 found also in Mi/omenippe granulosa, A. M.-Edw., in which they 

 are very deep ; they are, on the contrary, very shallow and often 

 scarcely distinct in Menippe RumpMi, Fabr. In Myom. granu- 

 losa the regions are very prominent and covered with granules, 

 while in Men. Rumphii they are only partly indicated and smooth. 

 Though the upper surface is smooth and glabrous, it is, however, 

 punctate, especially on the antero-lateral portions and on the 

 gastric region ; the punctations are generally minute, but some 

 larger ones are scattered over the hepatic region, on the proto- 

 gastric lobes, and on the arcuate sutural line, which occurs on 

 each side of the gastric region. 



The slightly prominent front is rather narrow, the distance of 

 the internal angles of the upper orbital margins measuring 

 scarcely more than one fifth of the greatest width of the cephalo- 

 thorax. The front presents four obtuse rounded lobes; the 

 internal lobes are broad and rounded, and nearly twice as broad 

 as the external, which are much smaller, much less prominent, 



