Wood-boring Crustacea from Christmas Island. 185 



riorum, but the accessory spine on the inner side of the 

 dactylus (fig*. 13) is tridentate and there is a large spine with 

 a single row of comb-like teeth springing from the distal end 

 of the propodus in addition to the smaller doubly pectinate 

 spine present in L. lignorum. In the succeeding limbs the 

 accessory spine is simple and there are no pectinate spines on 

 the propodus. None of the thoracic limbs have the distal 

 segments provided with tubercles or blunt spines. The last 

 pair are less elongated than in L. lignorum or L. pfefferi. 



The endopod of the pleopods is narrowly oblong only in 

 the first pair; in the following pairs it becomes wider than 

 the exopod, and in the last pair, where the exopod is devoid 

 of seta3j the endopod has two short plumose setee on its distal 

 edge. 



The exopod of the uropods (fig. 14) without its terminal 

 spine is about as long as the outer edge of the peduncle, and 

 the endopod is about half as long again; both rami are 

 slightly curved. 



The dorsal surface is coloured by a varying amount of 

 black pigment forming an elegant and complex pattern. 



There are no ovigerous specimens in the collection and 

 none of those dissected proved to be males. 



Remarks. — Mr. Stebbinggave, in 1904 (Gardiner's 'Fauna 

 Maldive and Laccadive Archip/ ii. (3) p. 714), a key to the 

 four species of Limnoria then known. The species described 

 above falls into the third section of this key, having the epi- 

 pod of the maxillipeds longer than the basis, the exopodite 

 of the uropods not unguiform, and the rami of the uropods 

 not both very small. The two species in this section are 

 L. segnis, Chilton, and L. pfrfferi, Stebbing ; from the first 

 of these the present species differs in having the mandibular 

 palp well developed and consisting of three segments ; from 

 the second it differs in having the epipod of the maxillipeds 

 much more than twice as long as wide. From all four species 

 it is separated by the shortness of the peduncle of the uro- 

 pods, which does not exceed the exopod in length ; in all the 

 other species it exceeds the exopod and in L. antarctica and 

 L. pfefferi it is longer than the endopod. 



So far as I am aware, the only species added to the genus 

 since the date of Mr. Stebbing's paper is L. japonica, de- 

 scribed byMiss Richardson (Proc. U.S. Nat. Mus. xxxvii. p. 95, 

 1909). This species is characterized chiefly by the presence 

 of tubercles and ridges on the posterior part of the body ; the 

 exopod of the uropods appears to be unguiform as in L. lig- 

 norum, but no details are given as to the maxillipeds. A 

 point of some general interest is the presence on the antennule 



