58 Mr. R. I. Pocock on Tsometrus americanus [Linn.). 



smooth sulcus ; between this sulcus and the keels on each side 

 are a few granules disposed in two masses ; anterior portion 

 of cephalothorax between the anterior keels and the lateral 

 eyes and the posterior portion at the sides sparsely granular ; 

 the lateral eyes about equally distant from each other ; 

 median eyes separated by a space which is about equal to the 

 diameter of each eye. 



Tergites more or less granular, the first marked in its pos- 

 terior half by a transverse series of granules, which, almost 

 marginal in the middle, curves forwards at the sides ; the 

 third ^^•ith a short, median, longitudinal series of granules in 

 its hinder third and on each side a conspicuous, slightly 

 curved, transverse band, composed of many close-set granules, 

 which does not reach the lateral margin of the tergite ; the 

 second in appearance midway between the first and the third ; 

 the fourth, fifth, and sixth resembling the third, but having 

 the bands of granules more pronounced ; the seventh marked 

 in front with a median, short, granular prominence and on 

 each side two granular keels, which, curving towards each 

 other in front, unite some distance in front of the anterior 

 margin of the tergite. 



Sternites in part very finely and sparsely granular, dull- 

 coloured, shining and smooth oidy behind and in the middle 

 line. The fifth marked with four finely granular keels — two 

 median, parallel, longer j two lateral, posteriorly converging, 

 shorter. 



Stigmota slit-like. 



Tail robust, nearly parallel-sided, the fifth segment only 

 very slightly wider than the first, about five and a half times 

 the length of the cephalothorax ; intercarinal spaces very 

 feebly granular ; upper surface scarcely at all hollowed; the 

 fourtJi segment alone bearing in front a conspicuous depres- 

 sion ; the keels bluntly and almost evenly denticulated 

 throughout, the terminal granule of the superior keels of the 

 second, third, and fourth being alone a little more prominent 

 than the rest. The first segment furnished with ten complete 

 keels ; the second, third, and fourth with eight, the median 

 lateral keel being wholly absent on the third and fourth and 

 represented by merely a few granules on the posterior half of 

 the second ; in the fifth the granules of tiie inferior surface 

 show a tendency to arrange themselves in a definite series on 

 each side of and parallel to the median granular keel ; upper 

 surface of this segment nearly flat, bearing only a very shal- 

 low median sulcus. 



Vesicle feebly and bluntly granular below, with a more 

 conspicuous granule in)mediately beneath the aculeus. 



