MANX: ANTS OF TIIK BRITISH SOLOMON ISLANDS. 341 



Two workers in tlio series are abnormal. Each l)ears on one side 

 of the pronotum a single elevated tooth similar to those on qimlridrns. 

 The specimens might be considered as abortive atavistic approaches 

 to some ancestral form very close to quadridcns. On account of tiie 

 presence of these spines in a species where they are normally absent 

 I consider this character of too little importance to be used in sepa- 

 rating certain of the species into the subgenus Odontomyrmex. Type 

 — M. C. Z. 9,174. 



68. Pristomyrmex mexdaxai, sp. nov. 



Worhcr. Length 2.25 mm. 



Near P. lucidus Emery. Head as broad as long, with slightly rounded 

 sides, broadly rounded occipital corners and subtruncate posterior border. 

 Cl>T)'eus flat, carinate at base; anterior border tridentate, the lateral teeth 

 acute, the median one obtuse. Frontal carinae acute; antennal scrobe broad 

 and shallow. Base of mandibles with large obtuse tooth, blades quadriden- 

 tate. Antennal scapes slightly surpassing occipital corners; funicular jomts, 

 except the first and those forming the club, somewhat broader than long. Eyes 

 small and slightly convex, situated at sides of head a Uttle in front of middle. 

 Promesothorax convex in profile, without pronotal spines and with obtusely 

 angulate inferior corners; with a broad median impression extending along 

 the dorsum to declivity of epinotum. Epinotal spines broad at base and 

 acuminate and curved apically. Epinotal declivity concave and broadly 

 margined at sides. Petiolar node as long as peduncle, higher than long; high- 

 est in front; convex above; concave on posterior surface; from above, longer 

 than broad and narrowed anteriorly, truncate behind. Postpetiole broader 

 than petiole and slightly broader than long, with straight borders in front 

 and behind and sUghtly convex sides. The anteroventral margin acutely 

 angulate in profile. 



^'ery shining. Mandibles finely punctate. Head and thorax with scattered 

 and shallow punctures, the spaces between smooth. Petiole, postpetiole, and 

 gaster sparsely and finely punctate. 



Everj-where with moderately abundant fine and long pile. 



Uniformly brownish red. 



Santa Cruz: Graciosa Bay. 



Two workers found beneath stones. This species resembles lucidus 

 Emery, but is smaller and differently colored, the promesonotal dorsum 

 is strongly impressed and the middle tooth on the border of clypeus is 

 not acute. The closely related P. Icrigatus Emery has the sides of 

 prothorax denticulate in front. 



