i88 



but the ventral hook is still considerably shorter. The other new species and varieties of this 

 group closely approach to some known forms, the differences are in general not striking. 



Syii. Theophane of the Paulsoni group much approaches to Syn. himidomamis (Paulson), 

 but the spinules on the upper surface of the telson are arranged in a rectangle that is wider 

 than long. A more interesting form is the new Syn. ancistrorhyncJms from the Jedan Islands, 

 which is related to Syn. acanthitelsonis by the shape of the telson, but the merus of the third 

 legs bears three feeble movable spinules and the frontal spines are curved upward like barbed 

 hooks. The characters of the two other new species, Syn. gracilirostris and Syn. hi/arti/ns, 

 are less conspicuous. 



The acquisitions made in the Biungidculatus group are more interesting. As far as I 

 am aware, in all the Indopacific species of this genus the posterior margin of the 6''^ abdominal 

 somite is entire. Now the expedition of the "Siboga" has discovered no less than 6 different 

 species, all pertaining to the Biimgniculatus group, in which species the posterior margin of 

 that somite is armed with 2, 3, 4 or 7 spines or acute teeth; these species, however, not only 

 differ from one another by the number of teeth with which the 6* abdominal somite is armed, 

 but also by many other features. Another remarkable form is the new Syn. bihiberculatns^ 

 represented by several specimens ; different from all other species, except Syn. septemspinosus^ 

 the large chela ends anteriorly in two conical tubercles, instead of one as usually. As a quite 

 interesting form ought also to be considered Syn. Antenoj% not only on account of the extra- 

 ordinary slender form of the antennular and antennal peduncles, of the telson etc. but also on 

 account of the fact that this species belongs to the largest representatives of the genus. This 

 species, however, is not new, for it has already been described by me in 18S8 under the name 

 of A. 6inngmculat?is Stimps. 



Except, perhaps, Syn. carifiahis (de Man) var. binongcensis^ Syn. odo7itophorus and Syti. 

 streptodactylus, all the Indopacific species of this genus, as far as we are aware, are inhabitants 

 of shallow water: of 13 species and 4 varieties, indeed, the depth at which they have been 

 obtained, is still unknown. Twenty six species and 6 varieties have been taken not deeper than 

 54 m. or 30 fathoms, but four of them, Syn. Nilandensis var. oxyceros., Syn. acanthitelsonis^ Syn. 

 bitmgtitculatus and Syn. Pescadorensis^ like also Syn. fossor., paraneomeris, htdulensis ., laticeps, 

 pachymeris and bitrnguiculat-iis var. exilipes extend perhaps to a depth of 90 m. (H. Coutiere, 

 Alpheidae Maid, and Laccad. Archip. 1905, p. 852). The following sj^ecies have also been 

 taken in deeper water, not deeper, however, than 113 m.: 



Syn. consobrinus de Man 



Syn. odontophoriis de Man 



Sy7i. neomeris (de Man) 



Syn. Gravieri Cout. 



Syn. Iphinoc de Man 



Syn. streptodactyhis Cout. 



Syn. locasta de Man 



Syn. Nilandensis Cout. 



Syn. Nilandensis Cout. var. bandaensis de Man 



Syfi. /iastilicrass2ts Cout. 



Syn. Iiastilicrassns Cout. var. 



Syn. triacant/ms de Man 



Syn. quadrispinostis de Man 



Syn. trispinostts de Man. 



Syn. nept^mus (Dana) 



Syn. Antenor de Man 



Syn. rnerospiniger Cout. 



56 



