728 BuUciin American Museum of Natural History. [Vol. XXIII, 



23. Myrmicocrypta brittoni sp. no v. 



Worker. (PL L, Figs. IS and 19.) Length: 2.3-2.5 mm. 



Head, without the mandibles, about as broad as long, slightly broader behind 

 than in front, with obtusely excised posterior border, rather straight sides, rounded 

 posterior corners and a narrow median longitudinal groove. Eyes distinctly in 

 front of the middle, of moderate size and convexity. Mandibles large, convex, 

 with straight outer and inner borders, the latter with about ten teeth which grow 

 gradually smaller towards the base. Clypeus short, with entire, flattened and very 

 broadly rounded anterior border. Frontal carinee with flattened but slightly 

 reflected lobes, which are much longer than broad, with roundly angular external 

 edges reaching only half the distance between the median line and the external border 

 of the head. Mesially these lobes are fused with the posterior portion of the clypeus 

 and enclose the small, indistinct frontal area which is triangular and longer than 

 broad. The lobes of the frontal carinte are not continued behind in the fonn of 

 diverging ridges as in other Attii. Lateral carina? sharp and distinct, continued to 

 the posterior orbits and bounding a broad, short and deep antennal groove. There 

 are no postorbital carinae. Antennae rather slender; scapes slightly curved at the 

 base and enlarged towards their tips, which slightly surp'ass the posterior corners 

 of the head; funicular joints all considerably longer than broad, terminal joint 

 nearly as long as the four preceding joints together. Thorax long and rather- nar- 

 row, in front about f as broad as the head. Pronotum with small, acute inferior 

 angles. There is a pair of blunt epinotal teeth, but otherwise the thorax is smooth 

 and without spines or projections. Mesoepinotal constriction distinct, but long 

 and rather shallow. Humeral angles rounded, mesonotum about as long as the 

 pronotvun, elongate ellijDtical, flattened, slightly higher than the epinotum. Epino- 

 tum with subequal base and declivity, the former straight and horizontal, the latter 

 concave and sloping, without longitudinal ridges. Metasternmn with a small 

 rounded tubercle on each side. Petiole oblong, a little broader than long, with 

 slightly rounded anterior and acute posterior corners; node evenly convex above, 

 suddenly constricted anteriorly into a very short peduncle. Postpetiole nearly 

 twice as broad as the petiole, somewhat broader than long, with straight posterior 

 border, rounded anterior corners and straight, subparallel sides; convex and evenly 

 rounded above without a posteromedian impression. Gaster smaller than the 

 head, longer than broad, elliptical, with straight anterior border and convex upper 

 surface, without lateral ridges or median impression on the first segment. Legs 

 slender, hind femora straight and without an angular projection on the flexor side. 



Opaque throughout; mandibles slightly glossy, very finely and densely striated; 

 remainder of body very densely and uniformly punctate. 



Hairs short, glistening white, dilated and scale-like, appressed, uniformly dis- 

 tributed over the body and appendages. Antennal funiculi and tarsi with delicate 

 whitish pubescence. 



Black; clypeus, antennal grooves, inferior corners of pronotvun, antennal scapes, 

 coxse and legs, dark brown; mandibles, except the teeth, tips of scapes, funiculi, 

 tarsi and articulations of legs light brown or yellowish. 



Porto Rico: Santurce (Wheeler). 



Though at once recognizable as an Attiine ant, this species is neverthe- 



