CEUSTACEA OF THE MEEGUI ARCHIPELAGO. 61 



acute tooth is present on each side, which is separated from 

 the median lobes and from the obtuse, slightly granular, internal 

 orbital angles on each side by a small cleft. The orbits have the 

 usual size and form ; the upper orbital margin presents two 

 fissures by which it is divided into three portions, the two external 

 of which are covered with a few granules,' whereas the much 

 larger internal portion is almost smooth. 



The external orbital angle is little prominent, and not spiniform; 

 it is separated by a small hiatus from the inferior orbital angle, 

 which is denticulate, being armed with six or seven acute teeth 

 besides the also denticulate internal lobe, which projects as much 

 forward as the external frontal teeth. The antero -lateral margins 

 are shorter than the postero-lateral ; they are armed, behind the 

 little prominent external orbital angle, with three acute, dark- 

 pointed, spiniform teeth. The external margin of the first antero- 

 lateral tooth, i. e. the outer orbital angle, is minutely denticulate, 

 and the external margin of the second antero -lateral tooth, which 

 is spiniform, is also somewhat granular at its base. The external 

 margins of the two posterior antero-lateral teeth are quite smooth. 

 A subhepatic spine which occurs in so many species of this genus 

 is wanting in JP. Andersoni, its place being occupied by a small, 

 somewhat prominent, acute granule. The postero-lateral margins 

 are straight and very slightly concave. The posterior margin of 

 the carapace is bordered by an impressed line, running close to 

 and parallel with it. The external antennae are long, measuring 

 twice the distance of the internal and external angles of the 

 orbits, and they reach almost to the penultimate antero-lateral 

 spine. When the cephalothorax is viewed from above, the an- 

 tennal peduncle is visible in the cleft or hiatus that separates 

 the internal orbital angles from the external frontal teeth ; its 

 basal joint, which scarcely reaches a process of the external 

 frontal tooth, is twice as long and nearly twice as broad as the 

 next or penultimate joint. The terminal joint projects beyond 

 the front, and is scarcely shorter than the second joint. 



The subhepatic and pterygostomian regions of the carapace 

 are covered with a short down and with numerous minute 

 granules ; those which are found on the anterior portion of the 

 subhepatic region are a little larger than the others. The endo- 

 stome is distinctly longitudinally ridged. The anterior margin 

 of the epistome is granular, the posterior margin, i. e. the anterior 

 margin of the buccal cavity, is sharp, and similar to that of 



