102 



Annals of the Transvaal Museum. 



This species does not seem to be abundant in the Transvaal, its 

 numbers being- far surpassed by one of its varieties, imprcssum. I 

 have never been able to obtain an engorged female so as to be able to 

 rear the various stages of the life-cycle. A comparison of the few 

 specimens which I have collected, however, reveals the following 

 variations from the description as given by Neumann. The male is 

 much smaller than jN^eumann states, and the outline of the body is 

 altered l)y the posterior end being cut off almost square, or truncate. 

 The shield is never lighter in the middle, and the median festoon 

 was never found to be white. The cervical projections of the shield 

 are much shorter than indicated in JN^eumann's figure, as is also the 

 length of the rostrum. But the greatest difficulty exists in the 

 punctuations of the shield. Instead of the punctures being evenly 

 distributed over all the shield, those in a triangular, sunken area, 

 whose base is the caudal margin, are confluent, rendering this area 

 shagreened. The female varies only in one respect, i.e. the lateral of 

 the three grooves in the dorsal surface of the body in the unengorged 

 specimen does not branch into two unequal arms, but remains single. 



This species is so variable that it was originally described under 

 a large number of names, as shown by the long list of synonyms. 

 Neumann was the first to study the various types carefully and bring 

 them together under one name. He, however, noted three frequent 

 variations from the type, and described them as varieties of the 

 species. 



HYALUMMA AEGYPTIUM, var. IMPHESSUM. NEUMANN. 



H. aegyptniin (Linn.), var. iinprcsRu iu , Neumann (1901). 



Plate 1', figures a to d, (j to in, o, p. 



Male. — Differs from the type species in the following characters : 

 Dorsal surface widely rounded behind and not truncate; larger than 

 the type, length 4.3 to 5 mm. (without rostrum), width 3.0 mm. to 

 3.5 mm. SJiield (I , a) convex; punctuations equal, small and so 

 abundant as to render the surface shagreened, instead of unequal 

 punctuations and a posterior triangular shagreened area ; cervical 

 grooves longer, but posterior grooves, marginal grooves, and caudal 

 festoons almost obliterated ; shagreening more marked towards the 

 edges ; median festoon rectangular, elongate ; lateral tail of stigmatic 

 plates narrower and longer (1, o). 



Female. — Differs from specific type as follows : (Unengorged) 

 larger than type, 6 mm. long by 4 mm. wide. Body (V , c, d) 

 elliptical in outline, widely rounded behind and not truncate as in 

 type; shield larger, 2.75 mm. long, and nearly as wide; punctuations 

 equal, fine, very abundant, making the shield shagreened; cervical 

 emargination deeper ; cervical and lateral grooves not so strongly 

 marked. Dorsal surface (F, c) in unengorged female more thickly 

 and deeply punctured. 



Nymjjh. — (Only this variety has, with us, laid eggs and 

 development followed in confinement.) Body (unengorged) broadly 



