iS6 



COB 



9. TETRASTEMMA SIGNIFER sp. nov. 



pi. XIV, figs. 9-11 ; XXI, figs. 10-12. 



Body of moderate proportions or somewhat elongated for the genus, 

 rounded throughout ; not very changeable in shape. Head of mod- 

 erate size, somewhat narrower than body, marked off from parts im- 

 mediately following by rather conspicuous oblique lateral grooves ; a 

 second pair of similar oblique grooves lies farther forward on head, as 

 shown in p1. xiv, fig. 11. 



Color. — General color of body deep reddish brown or purplish 

 throughout esophageal and intestinal regions. In the intestinal region 

 the color is rather more opaque than it is farther 

 forward. Ventral surface of the same general 

 color as dorsal, but of a duller tone, and often 

 much paler in the median line. This paler 

 median band is sometimes quite distinct in the 

 anterior esophageal region. A little back of 

 the posterior pair of oblique lateral furrows the 

 reddish color of body suddenly ceases, and the 

 whole head is white, or colorless, except for a 

 characteristic large dorsal marking. This mark- 

 ing is of a deeper brown and less reddish color, 

 and is usually situated just anterior to the poste- 

 rior pair of ocelli, although the relative position 

 of these parts is largely dependent on the state 

 of contraction of the head. 



In shape the marking resembles a wreath in 

 heraldry (pi. xiv, figs. 9-1 1 ; text fig. 20), hav- 

 ing a transverse, posterior or basal portion from 

 which two semicircular branches pass anteriorly, 

 but do not usually join. A fourth portion of the 

 figure passes forward in the median line from the basal portion to the 

 anterior ends of the semicircular lateral bands, but does not usually 

 join them. All these parts of the marking have irregular edges so 

 that the wreath-like effect is made still more striking. The general 

 effect is often that of an open wreath with vertical crossbar and sub- 

 stantial base, the whole figure appearing upon a white field. The 

 wreath is not always open, for one or both of its anterior ends may 

 join the anterior end of the median longitudinal bar. The whole 

 figure is surrounded by white, and is separated from the reddish 

 brown of the esophageal region by a fairly wide band of the same 



Fig. 20. T. stgnifer. 

 Outline of anterior por- 

 tion of body, showing 

 shape of cephalic mark- 

 ing and arrangement of 

 ocelli. X35- 



