NEUE BEITRÄGE ZUR ARTHROPODEN-FAUNA NORWEGENS. 219 



Tarentula pulverulenta (Glk.) 1757. 



This species occurred very commonly throughout the col- 

 lections, and its identification was an interesting but by no 

 means satisfactory matter. Forms more or less identical with 

 the generally accepted type were associated with varieties exhi- 

 biting very considerable modifications, in size, colouring, struc- 

 ture of the genital organs and relative lengths of legs and 

 céphalothorax. Nor did one variety occur only in one locality; 

 for in many cases a single collection contained a series of forms 

 of which the extreme types might easily have passed as distinct 

 species, had it not been for the presence of numerous inter- 

 mediate forms. The typical T. pulverulenta female has a 

 cephalothoracic measurement of 3 — 4 mm,, with tibia -{- pa- 

 tella of the fourth pair of legs less in length than the céphalo- 

 thorax. T. aculeata is a recognised variety with a cephalo- 

 thoracic measurement of 4 — 5 mm., equal to the tibia -|- patella 

 of the fourth pair of legs. In the present collections there 

 occurred varieties exceeding even the largest T. aculeata in size 

 but with the relative proportions of the typical T. pulverulenta. 

 The males, which occurred in fair numbers, were equally un- 

 manageable with the females. The transverse angular process 

 upon the central portion of the palpal organs exhibited a very 

 considerable variation in form, approaching by different degrees 

 tlie shape which occurs in T. aculeata, T. fabrilis and T. cune- 

 ata. It would seem highly probable that some, at least, of the 

 species nearest to T. pulverulenta will finally have to be con- 

 sidered co-specific with that species; but the whole question is 

 a very involved and difficult one, and one which could not be 

 satisfactorily dealt with except by the examination of types of 

 this group from all parts of Europe. 



Tarentula aculeata (Clk.) 1757. 



A few typical forms of this variety occurred, in company 

 with others intermediate between it and T. pulverulenta. 



