224 bulletin: museum of comparative zoology. 



divergent than in the genotype, and enclosing between them a deep 

 cavity, while the distal part is subtriangular with the end rounded. 



G41. Trigoniulus tahitianus, sp. nov. 



Type.— M. C. Z. 4,853. Paratypes.— M. C. Z. 4,854, 4,879. 

 Society Islands: Tahiti. 



Color greyish to bluish black with the caudal border of metazonites ferrugin- 

 ous, the ferruginous stripe widening down the lower part of the sides. Collum 

 solid black or nearly so excepting a narrow ferruginous border. Anal segment 

 dark, bluish black, excepting a narrow caudal border of ferruginous, to the 

 scutum and the mesal borders of the valves also sometimes ferruginous or this 

 color suffusing the entire surface. Antennae and legs ferruginous. 



Surface of head smooth and shining. Sulcus fine, widely interrupted in the 

 frontal region. Eyes not fully twice their diameter apart; subtriangular but 

 with all the angles rounded; oceUi in seven series, e. g., 5, 7, 8, 7, 6, 4, 2. 

 Antennae short, reaching only to caudal edge of the collum. 



Collum strongly narrowed down each side as usual, the caudolateral corner 

 rectangular, the anterior one rounded. Lower and anterior border up to 

 level of eye strongly margined, no striae above the deep margining one. 



Second tergite extending but slightly below level of the' collum, flattened 

 beneath. Segments most with obvious furrows along position of the suture, 

 this marked above and part way down the side below the pore with a series of 

 horseshoe-shaped impressions. Metazonites below with the usual striae, 

 these sparser and shorter dorsad. Second and several succeeding prozonites 

 with numerous complete cross-striations over the dorsum, there the continua- 

 tion of oblique striolatioiis below level of ix)re. Caudally these break up into 

 shorter curved marks, the latter soon becoming very short, sparse, and puncti- 

 form, while the prozonites in the posterior region appear almost wholly smooth 

 and unmarked. 



Anal segment smooth and shining. Scutum equaUing the valves. The 

 latter strongly margined. 



Numlicr of segments, forty-eight or forty-nine. 



Width (female), 3.1 mm. 



Phagostrophus, gen. nov. 



Lacking pads on tarsi of anterior legs of male. Most closely related 

 to Sympastrophus in structure of male gonopods. Anterior median 

 plate with distal tongue obviously angulate on each side, somewhat 

 diamond shaped with distal end narrowly rounded, to elliptic instead 

 of being broad and deeply incised. Coxal piece of anterior gonopods 



