I DiUTIFI CATION 



Male . The scutiim measures from 3.% mm. to 4.37 mm. in length 

 and from 1.95 ram. to 2.90 mm. in viidth; specimens with a scutum 

 measviring less than 4.10 mm. long and 2.66 mm. wide are uncommon. 

 ^The scuttim of H. excavatum measures from 3.52 mm, to 4.18 mm. 

 long and from 2.150 mm. to ^119 mm. iri.de, but seldom exceeds 3.75 

 mm. in length and 2.09 mm. in width^ The appearance is that of 

 a strong hyalorama in comparison with the typical frail guise of 

 H. excavatum . The shiny dark brown scutum is in contrast to the 

 Typically yellowish brovm scutiim of H. excavatum . Scutal p\mcta_ 

 tions are few; minute but distinct punctations are widely scattered 

 over the entire surface and become dense in the characteristically 

 triangular caudal depression; large punctations ntmiber no more 

 than those on the specimen illustrated (Figure 331) and may be 

 even rarer. Lateral grooves are strictly confined to the posterior 

 third of the scutum where they are deep and distinct. The caudal 

 depression is an approximately eqtiilateral triangle (margins curved 

 in H. excavatum ) boiinded by a ridge that is not so elevated as in 

 H. excavatum ; the apex of the depression is level with the apex 

 of the lateral grooves; the posteromedian groove is poorly devel- 

 oped and does not extend beyond the depression, the paramedian 

 grooves are faint, rounded depressions extending as faint grooves 

 to the middle of the third pair of festoons. The posterior margin 

 of the scutim is bluntly rounded while that of H. excavattmi is 

 more narrowly rovinded. The adanal shields are "strong, broad, and 

 quadrate posteriorly (Figure 332), and the subanal shields, that 

 lie directly posterior of them, are larger than is usual in H. 

 excavatum . The spiraciilar plate (Figure 332G) is distinguished 

 from that of H. excavatum (Figure 332F) especially by the narrow- 

 ly tapered, v'ery slightly curved tail (the tail of H. excavatum 

 is wider and curves more abruptly apically) . "" 



Female . Scutal meas\ireraents in most specimens are approx- 

 imately 2.50 mm. in length and 2.38 mm. in width; the minimum is 

 1.95 mm. by 2.00 mm.; the maximum 2.71 mm. by 2.52 mm.; the out- 

 line is subcircular and the surface is smooth with very few, 

 large, widely scattered punctations, thus being similar to that 

 of H. detritum (the typical outline in H. detritum tapers more 

 abruptly from the level of the eyes and''is narrower posteriorly) . 

 The genital apron (Figure 334A to D) is similar to that of H. 



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