THE AYEST AMEBICAN SCIENTIST. 43 



MOLLUSKS OF SAN DIEGO.-III. 



[Continued from page SO. ] 



The Fiisidae family contains more or less spindle-shaped shells, without var- 

 ices; the lip of the aperture not thickened. The only representative of this family 

 which I have found at San Diego is a single beach-worn specimen of Fusus kobelti 

 var. unicolor, which was about two inches long. The variety differs from the type 

 in being more slender and in the absence of the usual chocolate color on the larger 

 riblets. 



SiphonaKa Eellettii, a large, stout white shell which is rarely found at San 

 Diego, but has been dredged alive in 16 fathoms off Catalina Island harbor in 1873, 

 forms a representative of the Buccinidae family. Large numbers of dead shells of 

 this are sometimes washed ashore at Todos Santos bay, Lower California. The 

 other representative of the family is the Macron lividus of A. Adams, which is not 

 rare on the ocean beaches, where it may be found on the rocks at the edge of the 

 water at very low tide. 



Th3 Nassidae are known by several species of Nassa, a genus of world-wide 

 distribution. Our species are: 



Nassa fossata, Gould, dea I shells of which are abundant, apparently living in 

 deep water; Nassa perpinguis. Hinds, seemingly rare at San Diego, though not rare 

 at Catalina in 16 fathoms, and dead shells are plentiful; Nassa mendica var. cooperi, 

 Fbs., rare at low water at La Play a, also at Todos Santos bay; and Nassa tegula, 

 Rve., abundant on muddy bay shores, where they may often be found coU.cting to 

 feist on some dead animal. 



\_To he continued. 1 



FOREST INFUENCE ON CLIMATE. 



In a paper before t .e Royal Me.eorolo^ical Society of London, Dr. Woeikof 

 stated that the first step towards a scientific investigation of the influence of forests 

 upon climate was taken by th j establishment of the Bavarian forest meteorological 

 stations. This example was followed by Germany, France, Switzerland, Italy and 

 other countries. In general it has been found that during the warmer season the air 

 and earth temperatures are lower in the forest than in neighboring woodless pieces; 

 that their variations are less, and that the relative humidity is greater. A discus- 

 sion of this question shows that in the western portions of the Old World extensive 

 forests materially influence the temperature of neighboring localities, and that the 

 normal increase of temperature of the Atlantic ocean towards the interior of the 

 continent is not only interrupted by their agency, but they cause the summer to be 

 cooler in regions situated further in the interior than those nearer the sea. Hence, 

 forests exert an influence on climate which does not cease at their borders, but is 

 felt over a greater or less district, according to the size, kind and positions of the 

 forests. It follows from this that man may considerably affect the climate by clear- 

 ing forests in one place and planting others in another. 



