CRUSTACEA OF THE MEEGUI AECHIPELAGO. 



155 



The chelipedes of the male are, in most species, more or less 

 elongate, the palm being nearly always longer than broad. Arms of 

 the anterior legs of the male with "musical crest." Ambulatory 

 legs similar to those of Helice, those of the penultimate and 

 antepenultimate pair being equal in length, and much longer 

 than the legs of the second and fifth pair. 



Though this genus is closely allied to Selice I am, however, 

 inclined to retain it, including in the genus o£ de Haan (the type 

 of which is Helice tridens) those species which have the cephalo- 

 thorax rather thick and more or less convex above, and the 

 ehelipedes short, with the palm higher than long. The genus 

 Metajplax, on the other band, may contain those species with a 

 thinner and more depressed cephalothorax, which have the anterior 

 legs more or less elongate, and the palms of the hands longer 

 than high. 



The genus Faragrapsus, M.-Edw., of which I have been enabled 

 to examine two species through the kindness of Prof. A. Milne- 

 Edwards, is also closely allied to Metaplaoc, but differs by the 

 front being much more prominent than the epistome. 



The genus Metaplaon, as now defined, includes seven species, 

 all of which inhabit the Oriental seas ; five are described in this 

 Eeport, the other two being Metap. indicus, M.-Edw., and Metap. 

 longipes, Stimps., from Hongkong. 



The five species of this collection may be distinguished thus : — 



' spinulose along the upper or anterior margins cren%latus. 



Oarpopodites 

 and propodites ^ 

 of the ambula 

 tory legs 



not spinulose 

 along the upper 

 or anterior mar- 

 gins. Number 

 of lobules or \ 

 teeth of the in- I 

 fraorbital ridge 

 in the male 

 amounting to 



25-30. 



40-60. 



dentipes. 



Lobules of the 

 orbital portion 

 very large, 6 in 

 number in the 

 adult male, and 

 rapidly decreas- 

 ing in size 



Lobules of the 

 orbital portion 

 small, 10-12 in 

 number, and 

 slowly decreas- 

 ing in size 



( longer than 



Palm of the J broad elegans. 



j hands of the as long as 



i^male ^^ broad intermedius. 



distinctus. 



