216 bulletin: museum of comparative zoology. 



611. ACANTHIULUS WOLLASTONI Hirst. 



Trans. Zool. soc. London, 1914, 20, p. 330, f. 17.i 

 Locality. — Dutch New Guinea: Mimika River.^ 



612. ACANTHIULUS MURRAYI PoCOck. 



Spirobolus dentatus Daday, Terra, fiiz., 1893, 16, p. 101, pi. 3, fig. 1-7.' 

 Acatdhhdus murrayi Carl, Abhandl. Senckenb. gescllsch., 1912, 34, p. 276.^ 



Localities. — ^ Aru Islands: Samang, Wokan, Ngaiguli, Teran- 

 gan, Dabo, Wammer,- Wokan Dabo.^ 



Plokamostrophus, gen. nov. 



Like Trigoniulus in having tarsal pads on the anterior legs of male, 

 but differing in having strongly developed processes on coxae of third 

 to seventh legs and in the structure of the gonopods. In these the 

 telopodite of anterior pair similarly distally broad but on mesal side 

 presenting a large distinct process or horn which extends distad beyond 

 end of principal part and distally bends more or less ectad; telopodite 

 not segmented. Anterior median plate distally truncate. 



Genotype. — P. amphelidm, sp. no^^ 



613. Plokamostrophus amphelictus, sp. nov. 



Type.— M. C. Z. 4,936. Paratypes.— M. C. Z. 4,937 and 4,938. 

 Solomons: Tulagi, Auki (W. M. Mann). 



General color black with most metazonites typically ferruginous below level 

 of pore and also on dorsum each side of median longitudinal dark stripe, the 

 dorsal spots typically more reddish; dorsally also the prozonites are paler 

 anteriorly. Legs ferruginous. 



Head with sulcus obscure or absent excepting in clypeal region in the lower 

 part of which it is deeply impressed. With several arcuate transverse striae 

 near level of antennae. Clypeal setigerous foveolae 2 + 2. Antennae short. 



Collum of typical Trigoniulus form. Second tergite not extending below 

 level of collum or scarcely so. 



Segmental striae distinct laterally but disappearing above in a shallow 

 transverse depression or furrow; widely curving opposite pore which is not in 

 contact with it. A transverse series of deep impressed dots and marks in 

 dorsal furrow, the dorsal surface otherwise essentially smooth. Below level 



