282 BULLETIN 54, UNITED BTATES NATIONAL MUSEUM. 



The palp of the mandible is composed of three articles. The frontal 

 lamina is lar^e and conspicuous and has the anterior margin broadly 

 triangulate, the post-lateral angles produced. 



The segments of the thorax are about equal in length. The epimera 

 are not distinct from the segments, but the place of coalescence is 

 indicated by a light longitudinal area on either side of the segment. 

 The post-lateral angles of the lateral parts of all the segments is drawn 

 out into a narrow and somewhat acute process, more pronounced in 

 the first four segments. 



The abdomen is composed of two segments. The first segment has 

 three suture lines indicating several partly coalesced segments. 

 The terminal segment is long and widely rounded posteriorly. The 

 anterior portion is convex. The fixed inner branch of the uropoda 

 extends a little beyond the extremity of the terminal abdominal seg- 

 ment and has its margins smooth. The outer movable branch is as 

 long and wide as the inner branch and has three or four teeth on its 

 outer margin. 



The legs are all ambulatory in character. 



SPHiEROMA DESTRUCTOR Richardson. 



SpJurroma destructor 'RicRAB.T>?.oii, Proc. Biol. Soc. Wash., XI, 1897, pp. 105-107; 



American Naturalist, XXXIV, 1900, p. 223; Proc. U. S. Nat. Mus., 



XXIII, 1901, p. 534. 

 Sphseroma tenebrans STEnmNG (part), Spolia Zeylanica, II, Pt. 5, 1904, pp. 16-21. 



Locality. — St. Johns River, Palatka, Florida. (Fresh water.) 

 Bores holes in piers on St. Johns River, Sections of the wood 

 show that the diameter had been reduced during a period of eight 

 3'ears from 10 inches to 7i inches. The whole surface of the wood 

 was bored with holes averaging in size about 5 mm. 

 in diameter, and in an end section the holes were 

 arranged in concentric rings between the rings of 

 annual growth, showing the little animal's preference 

 for the soft pine. Very strong mandibles projecting 

 beyond the labrum most conspicuously provide a per- 

 fect equipment for this destructive work. 



Head twice as broad as lojig, having a small 

 median projection. Eyes lateral and posteriorly 

 fig.294.-sph^eoma .situated. The first pair of antenna, with a flagellum 



DESTRUCTOR. DOR- i ^ • i , , • i i j^l • • 



s.ii, VIEW. X 3. composed oi eight articles, reach the posterior margin 

 of the head; the second pair of antenna extend to 

 the post-lateral angle of the first thoracic segment; its flagellum is 

 twelve jointed. 



The first and fourth thoracic segments are of equal length and are 

 one and a half times longer than the other thoracic segments. The 



