210 BULLETIN 182, UNITED STATES NATIONAL MUSEUM 



2. Punctures of pronotum and olytra strongly and distinctly united in channels, 



with intervening ridges very distinct 2. chapini 



Punctures of pronotum and elytra not strongly united in channels, ridges not 

 strong and distinct 3 



3. Densely punctate throughout, subopaque 3. rulomus 



Not densely punctate, shining 4. odius 



4. Fourth segment of anterior tarsus strongly bilobed 5 



Fourth segment not bilobed 1. trinitatia 



5. Head wiih median smooth space on vertex 6 



Head without median smooth space on vertex 10 



6. Punctures of pronotum and elytra coarse and deep, similar to those 



of head 7 



Punctures of pronotum and elytra fine and scattered, much less coarse than 

 those on head 17. lucens 



7. Abdomen punctured as forebody but less coarsely 8 



Abdomen with relatively fine shallow punctures and strong ground sculp- 

 ture 13. dyeri 



8. Pronotum tuberculate at sides of base 20. antillensis 



Pronotum not tuberculate at sides of base 9 



9. Head with large and well-defined additional smooth area both at each posterior 



upper margin of eye and behind each antennal fossa 14. cubanus 



Head without large and well-defined additional smooth area 17 



10. Subopaque ; length 2 mm 5. bakeri 



Shining; length 3 to 5 mm 11 



11. Punctures of elytra generally separated by nearly their diameter. 



6. jaraaicensis 

 Punctures of elytra generally separated by half or less of their diameter. 12 



12. Punctures of pronotum somewhat serial along midline behind center 13 



Punctures of pronotum not at all serial along midline behind center 14 



33. Eighth tergite with dense scaly ground sculpture 11. morrisoni 



Eighth tergite without distinct scaly ground sculpture 12. bryanti 



14. Pronotum as broad as long 10. mutchleri 



Pronotum distinctly longer than broad 15 



15. Outline of pronotum from above with a distinct postapical protuberance 



on each side 8. augustinus 



Outline of pronotum from above not interrupted near apex 16 



16. Pronotum much more densely punctate than elytra 7. jugalig 



Pronotum not much more densely punctate than elytra 9. haitiensis 



17. Median area of head narrow but very distinct and extending throughout 



length of vertex 16. darlingtoni 



Median area not extending throughout length of vertex 18 



18. Median area very broad, well-defined 18. bispaniolus 



Median area feeble, ill-defined 19 



19. Vertex with a small but distinct depression on each side of midline near 



center 15. adanisoni 



Vertex scarcely at all depressed 19. cubensis 



1. STENUS TRINITATIS, new species 



DescHpfion. — Shining black. Head rather deeply concave above 

 between the eyes, with a narrow acute median longitudinal ridge; 

 labrum broadly rounded ; with moderately fine irregularly shaped and 

 spaced punctures; without ground sculpture or sm.ooth areas except 



