ProccediiKjs of the South African Philosophical Society, xix 



by the structure of their bodies, which are very thick, while the 

 legs are very short. These spiders have powerful spines in a row 

 on their mandibles for burrowing, those which make their trap- 

 door nest in holes on trees being destitute of such spines. There 

 are al30ut thirty species of this group now known in South Africa, 

 about half that number being new to Science. Some make their 

 nests in holes in the ground, perfectly cylindrical at bottom, but 

 having the upper part somewhat wider and closed with a heavy lid. 

 The President, in thanking Dr. Purcell for his interesting paper, 

 congratulated him on the success which had attended his investiga- 

 tions into the habits and structure of such an interesting group of 

 animals. • . 



Mr. Charles Stewart read a paper on " The Hot Winds of 

 Namaqualand, with some reference to the Berg Winds of the South 

 Coast." 



The characteristic features of the winds of Port Nolloth, on the 

 west coast of Cape Colony (lat. 29° 14' S., long. 16° 51' E., and 

 26 feet above sea-level), and at O'okiep, about 50 miles inland to 

 the S.E., on an elevated plateau (3,036 feet above sea-level in 

 lat. 29° 36' S., and long. 17° 52' E.) were investigated by con- 

 structing " Wind-Koses " from observations taken simultaneously 

 at both places at 9 a.m. during January-September, 1900, in order 

 to verify the accuracy of an account furnished by the observers at 

 these stations. The results went to show^ that at Port Nolloth there 

 are two winds, viz., N.W.'ly and E.'ly, the average temperatures 

 of which are higher than the mean temperature at 9 a.m., while 

 at O'okiep the warm winds blow from N.E. and S.E. 



Special attention was directed to tlie E.'ly winds (i.e., those between 

 E.N.E. and E.S.E.) at Port Nolloth, which are hot and dry, and 

 usually accompanied by cloudless, or almost cloudless, skies ; these 

 are confined to the winter months, April-September, and their 

 approach is heralded by a reddish glare in the evening sky. They 

 are succeeded by cool, cloudy weather, which may or may not be 

 accompanied by rain. 



The N. E.'ly and E.'ly winds at O'okiep blow throughout the year, 

 Ijut their temperature, as in the case of the prevailing S. winds at Port 

 Nolloth, corresponds with the season, being cold in winter and warm 

 in summer ; they are occasionally accompanied by one or other 

 of the higher (Cirrus) clouds coming from N. or N.W. The S.E.'ly 

 winds seem to be of rare occurrence and confined to the summer 

 months. These summer E. and N.E. winds at O'okiep do not reach 

 Port Nolloth. 



