402 SPH^ROMID^. 



The body is of a more or less oval form, very convex, 

 and rounded at each end, thus differing from the Cymo- 

 thoae, which have the anterior part of the body much 

 narrowed. The head is broad and vertical, having a 

 frontal elevated transverse ridge which is continuous with 

 the lateral margin of the body. The eyes are very wide 

 apart, placed at the superior lateral angles of the head, 

 and received into an emargination on each side of the 

 first segment of the body. The antenna are inserted close 

 together in tlie middle of the anterior surface, on each 

 side of a small frontal prominence which is joined below 

 to the epistome ; they fall back and are protected (when 

 unemployed) by being lodged within a groove beneath 

 the lateral margin of the head and anterior segment of 

 the body ; the upper or inner pair are affixed at the sides 

 of a small triangular frontal prominence, and have a very 

 hroad and flattened, nearly quadrate, basal joint, fol- 

 lowed by a second smaller one ; the third as long as the 

 second, thin and cylindrical, followed by a short, slender, 

 articulated flagellum, consisting of about a dozen articuli. 

 The lower or outer antennse are considerably longer than 

 the upper, with the basal portion composed of four 

 moderately thickened joints and a multiarticulate flagel- 

 lum. The epistome is generally quite distinct from the 

 upper lip, and is produced above into a point, nearly 

 meeting the point of the upper triangular piece above 

 mentioned; on its lower edge it is very deeply emarginate, 

 receiving the base of the upper lip or labrum, of which 

 the anterior margin is nearly straight. The mandibles 

 are strong and horny, strongly angulated at the ex- 

 tremity, and terminated in that part by two slender 

 denticulated teeth, below which, on the inner margin, is 

 a large and strong molar tooth. Near the middle of the 



