222 bulletin: museum of comparative zoology. 



Styraxodesmus, gen. nov. 



Differentiated from Lophodesmus by having the penult tergite 

 strongly prolonged caudad as two stout submedian processes which 

 much exceed the last tergite. The last tergite is reduced and covered 

 from above by the penult; lobed, tuberculate. 



Pore tubercles on dorsal side of edge, extending upward, occurring 

 only on somites five, ten, thirteen, and sixteen, this pore arrangement 

 distinguishing the genus from Urodesmus Porath and Crypto- 

 gonodesmus Silvestri. 



Genotype. — S. furcatus, sp. nov. 



172. Styraxodesmus furcatus, sp. nov. 



r^pe.— M. C. Z. 4,479. Haiti: Jacmel, December, 1912. W. M. 

 Mann. 



Strongly, hemicylindrically arched above, with the keels depressed. 

 Brownish over a yellow ground. With tw^o submedian ridges or 

 combs formed of larger tubercles as in species of Treseolobus and 

 Lophodesmus. Of these large tubercles there are three in each 

 row on each tergite excepting in the anterior four or five when 

 there are but two. The upper surface of the keels is finely granular. 

 Free border of first tergite emarginate at the middle line in front; 

 divided by radial ridges into ten lobes of which those adjoining the 

 median line are shortest. Lateral margin of second tergite two-lobed 

 with the caudal of these more weakly again divided. Lateral margin 

 in other keels weakly bilobed, the emargination abrupt, narrow. 



Length about 4 mm. 



Homodesmus, gen. nov. 



This genus is like Treseolobus and Styraxodesmus in having the 

 first tergite extended forward so as to conceal the head. Antennae 

 short, almost wholly concealed in a groove beneath the edge of the 

 first tergite. The free margin of the first tergite is crenate and the 

 border is crossed by sulci defining tweh'e corresponding lobes. The 

 first and second tergites wider than the following ones. The dorsal 

 surface of all tergites densely and closel\' covered with rather large 

 tubercles which are of nearly uniform size, with no trace of the larger 



