THE FLORISSANT LAKE liASIN. 29 



em of" plants, it will appear that there are vast numbers of a sinj^le species ; 

 a great many specimens are represented by bodies only, or these accom- 

 panied by insignificant fragments of wings, but even putting all these aside 

 there remain a goodly number with tolerably perfect wings, and some in 

 which almost every part of the body is preserved ; taken as a whole, how- 

 ever, they are perhaps less perfect than specimens of almost any other fam- 

 ily. There are u dozen or more Stratiomyidjt , of two or three species, and 

 several species of Midasida- or Hirmoneurida?, one admirable specimen of 

 the latter family having been described as belonging to a new genus under 

 the name of Palembolus florigerus. There are nearly half a hundred Asi- 

 lidse and Therevidse, many of them exquisitely preserved, some of great 

 size, and among them a fair variety of forms. Bombylidne are somewhat 

 less abundant, but show some superb specimens of great size and in won- 

 derful preservation ; there are certainly six or eight species. Syrphidse are 

 more abundant than the last, nearly fifty specimens having been found in 

 which the patterns of the abdominal colors are generally well marked, and 

 among which we find a considerable variety; they liave been studied by 

 one very familiar with that group. Dr. S. W. Williston, and the results of 

 his examinations are given in his Synopsis of the North American Syrphidte 

 (pp. 281-283), published by the U. S. National Museum. There is a vast 

 host of Muscidas and allied groups, of Avhich no account has yet been taken, 

 and with which no doubt many other forms are still commingled, but three 

 or four species of very pretty Ortalidse may be mentioned with ten or a 

 dozen specimens, and there are a large number of Empidae. 



A few Lepidoptera occur. The butterflies, seven in number, have been 

 described in the Eighth Annual Report of the present Geological Survey. 

 They all represent distinct and extinct genera. Six of the seven belong to 

 the Nymphalida?, the seventh to the Pierinse. Of the Nymphalidaj all but 

 one are Vanessidi. The exception is of special interest, since it belongs to 

 the Libytheinae, the family of living butterflies the most meager in numbers, 

 though found in every quarter of the globe. To be able to add that still 

 an eighth butterfly, found since the others were described, belongs to a 

 second extinct genus of Libytheinjii (which I have called Barbarothea) is 

 certainly marvelous. Besides these I have set aside about a dozen speci- 

 mens of perhaps eight species of moths, but they are obscure, mostly of 

 small size, perhaps Pyralidse or Tortricidse, and, excepting one described in 



