Mr H. D. S. Goodsir on two New Species of Leachia, 309 



of the year when the barometer is lowest. Farther, it is im- 

 portant to observe, that some recent writers have, on appa- 

 rently very plausible grounds, attributed the depression of the 

 barometer to the influence of electricity on the atmosphere.* 

 It has long been known that electricity is generated in great 

 abundance in the earth, and that it passes in various forms, 

 though most frequently imperceptibly, into the atmosphere. 

 Would it be an irrational conjecture, that the production of 

 earthquake-shocks, at least in non-volcanic countries, is due 

 to the states in which the atmosphere are relatively to each 

 other ? If, as there is reason to suppose, electricity is formed 

 in the interior of the earth most abundantly during winter, 

 does this circumstance not serve to explain the greater fre- 

 quency of shocks in that season \ and may the shocks not be 

 caused by occasional discharges of electricity from the earth 

 into the atmosphere — ^not unlike to discharges from one cloud 

 to another \ 



[In the next number there will be a continuation of the Register of Shocks 

 in Great Britain, and especially in Scotland, during the years 1839, 1840, 

 and 1841, with an abstract of the phenomena which accompanied them.] 



On two New Species of Leachia. By Henry D. S. Goodsir, 

 Esq., Surgeon, Anstruther, Fife. With a Plate. Communi- 

 cated by the Author. 



Among a number of undescribed Crustaceans which have 

 from time to time occurred to me at the mouth of the Frith 

 of Forth, are two Idoteae, referable to the genus Leachia of 

 Johnston.t 



1 . Leachia intermedia. (Mihi^ 



L. Antennis superioribus longioribus articulis duobus primis inferio- 

 rum ; ultimo articulo minute et globoso ; quarto segmento thoracico 

 serie tuberculatum utroque latere amborum cardinum longitudinalium 

 instructo. Long. lin. 4.6. 



* See a paper by M. Tassau, road at the Societt? Philomathique of Parisi 

 as quoted in L'Institut of 10th June 1841 ; and also a paper by Mr Rowell, 

 read at the G lasgow Meeting of the British Association (p. 4G of Brit. Assoc, 

 Report for 1840). 



t Edin. Phil. Jour., vol. xiii, p. 219. 



