7fi Miscellaneous. 



In the *2nd volume of tin- ' S\ nop!<is of tlie Britisli Diatomacese,' the 

 Rev. "NV. Smith states, that he lias never observed this siliceous sheath, 

 and that " j)robably it may have been an appearance resulting from 

 the condensation and corrugation of the mucus developed around the 

 reproductive body." 



I need scarcely say that Mr. Smith's conclusion is untenable, for 

 no kind of mucus will jesist the action of a red heat and nitric acid. 

 Moreover, the specimen was not an isolated one, but hundreds of them 

 were j)rcsent. It is, however, perhaj)s excusable that Mr. Smith 

 shoidd consider me as having been misled by an appearance, having 

 himself mistaken the cellular appearance upon the valves of the 

 Diatomacese for the expression of a cellular structure. 



In regard to the "blunder" committed by Dr. Uassall in the 

 formation of the name GyrosUjmu (which is not alliterative however), 

 I may remark, that this name was retained in the ' Micrographic 

 Dictionary ' and elsewhere, because it had claims from ]jriority, and 

 from its adoption by Kiitzing and Rabenhorst ; also because, although 

 objectionable in structure, it was less so than the name Pleiirosiymu, 

 considering that no two authors agree as to which is the side of a 

 Diatomacean frustule. 



Again, the objection to the name Gyrosiyma applies also to some 

 other established generic names, as Sjnroyyra, &c., the alteration of 

 which would cause great and unnecessary confusion. 



J. W. Griffith, M.D. 



9 St. John's Square, May 9, 1856. 



Travels in Central America. By MM. Scherzer and Wagner. 

 (Communicated by Count Marschall.) 



Dr. Scherzer lately communicated to the Imperial Academy of 

 Sciences at Vienna (March (3, 18.5G) a report of his travels through 

 the northern portion of Central America, undertaken, in company 

 with Dr. M. Wagner, in lH.52-.")y. A meteorological journal was 

 carefully kept during the whole journey ; and the altitudes of moun- 

 tains, plateaux, and volcanic peaks, together with the limits of the 

 diifusion of the most important among the animals and the cul- 

 tivable vegetables, were approximately determined by the aneroid 

 barometer. Intercourse with the savage Indian tribes, and residence 

 at villages of the settled and agricultural aborigines of Honduras, 

 San Salvador, and Guatemala, provided the travellers with valuable 

 materials for their ethnographical studies. The governments through 

 whose territories MM. Scherzer and Wagner passed most readily- 

 communicated a large amount of statistical and administrative infor- 

 mation. 



An extensive entomological collection was made in Costa Rica and 

 Guatemala ; and MM. Scherzer and Wagner brought home about 

 •40,000 specimens of Invertebrata ; among which are nearly 300 

 undescribed species (according to AIM. Klug and Hopffer, of Berlin) 

 of Coleoptera, Lepidoptera, andllymenoptera. There are also many 

 new and interesting forms among the land and freshwater Mollusca. 



