248 bulletin: museum of comparative zoology. 



Mesethodesmus, gen. nov. 



In general appearance resembling Scytonotus but composed of 

 head and twenty somites instead of nineteen. 



Antennae moderately long, strongly clavate to the sLxth article. 

 Articles excepting those at the ends constricted at base, strongly 

 thickened distally. 



First tergite somewhat narrower than head inclusive of mandibles. 

 All tergites (metazonites), including the first and anal, strongly 

 tubercular; the tubercles arranged mostly in six or more transverse 

 series, each bearing a long setose process and those along the caudal 

 margin, particularly in the posterior region, projecting as teeth or 

 serrations as in Peridontdesmus but not serrate anteriorly. Keels 

 with caudal corners rounded, not at all produced, more angular in 

 posterior somites. 



Repugnatorial pores occurring on the fifth, seventh, ninth, tenth, 

 twelfth, thirteenth, and fifteenth to nineteenth segments. The pores 

 in general on the dorsal side of the keel on a rounded or conical eleva- 

 tion which in the anterior region is median in position but in the 

 posterior somites is toward the caudolateral corner. Anal plate large, 

 triangular, pointed behind, densely tuberculate. Anal scale trapezi- 

 form, with two widely separated setigerous tubercles. 



Type. — M. haitianus, sp. nov. 



212. Mesethodesmus haitianus, sp. nov. 



Type.— M. C. Z. 4,532. 9. Paratypes.— M. C. Z. 4,533. 9- 

 Haiti: Furcy. W. M. Mann. 



General color above light brown, the caudal row of tubercles com- 

 monly pale. First tergite with a large yellowish area on each side. 

 Head yellow. Antennae yellow proximally, dilute brownish distally. 

 Venter and legs yellow. 



Head above very finely granular, with numerous very short, fine 

 hairs. Antennae strongly thickened distad; the sixth article espe- 

 cially enlarged elevated on the dorsal side, those proximad of this 

 elevated progressively less in going toward the base. 



First tergite somewhat semicircular, the caudal margin slightly 

 convex on each side, mesally emarginate; scarcely narrower than the 

 head with mandibles, broader than head without; obviously narrower 



