208 PROCEEDINGS OF THE NATIONAL MUSEUM vo; 



Table 2. — Length of elytra {in millimeters) for four species of Tetraonyx. 



and 3. It will be noted that the average size of the females is slightly 

 greater than that of the males. 



The sixth abdominal sternum in males from the United States has 

 relatively deep, regularly triangular, straight-sided emargination and 

 rather evenly tapered lateral lobes. On Hispaniola and Montserrat 

 the emargination is similar in form to the above but slightly shallower, 

 and the lateral lobes are more noticeably rounded on the lateral margin. 

 Males from Puerto Rico and St. Vincent differ from the rest in that 

 the angle of the emargination is much more obtuse, with the sides of 

 emargination definitely sinuate. 



The species Tetraonyx quadrimaculata is a member of a closely knit 

 and poorly understood complex that includes the Cuban forms 

 T. cruciata and T. maestra, the Brazilian T. himaculata Klug, and in 

 all probability T. maculata Haag-Rutenberg. We have not seen speci- 

 mens of the last form, which is recorded from southern Mexico and 

 Central and South America, but from its description we concluded 

 that it is intimately related to T. quadrimaculata. T. cruciata and 

 T. himaculata have long been regarded as varieties of T. quadrimaculata. 

 However, we prefer to regard them as separate species for the present. 



Table 3. — Proportions of pronotum and right elytron (in percent) for four species of 



Tetraonyx. 



' width measured at narrowest point between base and middle of elj'tron. 



