S. H. SCUDDER ON THE EARLY TYPES OF INSECTS. 



17 



The earliest known Diptera occur in the Liassic rocks at Cheltenham, Dumbleton and 

 Forthampton in England; the Lepidoptera : in the middle Oolite (Solenhofen) ; and the 

 Hymenoptera in the same formation. 2 The Metabola are then later in time and more per- 

 fect in development than the Heterometabola. 



When we analyze the insect fauna of the earliest times more closely, we notice that the 

 higher cuborders of Heterometabola, the Coleoptera and Hemiptera, are represented in the 

 palaeozoic rocks by very few types, as compared with the Orthoptera and Neuroptera ; the 

 two former groups having but three or four each, 3 while Golclenberg enumerates fifteen or 

 sixteen of each of the others from Saarbriicken alone, and double that number must be 

 known. No Coleoptera nor Hemiptera have yet been found in the palaeozoic formations 

 of America, while I am acquainted with about forty Orthoptera and Neuroptera from 

 these rocks. The almost entire absence of Coleoptera from palaeozoic rocks is the more 

 remarkable, because their crust is much thicker than that of other insects, and their shards 

 as hard as the shell of the body. This is peculiarly the case in the lowest and presum- 

 ably oldest type, the weevils or Curculionidae. Their remains have been preserved with 

 the greatest readiness in more modern strata ; in fact, in all the newer rocks, Coleoptera 

 are best represented of all insects ; yet in the oldest, very few have been found in com- 

 parison with the remains of the lower suborders. This is a striking and indisputable fact, 

 and notwithstanding the paucity of the material whereon to base a general statement, is 

 scarcely to be explained on any other hypothesis than that of the later appearance of 

 Coleoptera. 



In the Orthoptera again, nearly all the families represented belong to the lower series ; 

 only four or five members of the saltatorial families have been found, the cockroaches of 

 the Carboniferous period outnumbering all the other Orthoptera many times. In the last 

 catalogue of fossil cockroaches (by Goldenberg), thirty-five species are recorded from the 

 Carboniferous rocks and only seven from the Tertiary formation. Indeed about one-half 

 the known species of palaeozoic insects are cockroaches. 



Or, if we look at the Neuroptera, we find that the Neuroptera proper, or those with com- 

 plete metamorphosis, scarcely occur at all in the palaeozoic rocks ; whereas the lower 

 Pseudoneuroptera, with incomplete metamorphosis, are comparatively abundant. Many of 

 the reticulate-winged insects of early periods, however, combine the characters either of 

 the Neuroptera and Orthoptera, or of the Neuroptera proper and Pseudoneuroptera. So 

 striking, indeed, is the comprehensive nature of these early types that Dohrn, and after him 



1 The carboniferous Breyeria of de Borre (Comptes 

 rend. Soc. Ent. Belg., [2.] xm : 7-11) is universally con- 

 ceded to be a neu'ropterous insect. See the remarks in the 

 same journal by Hagen, Heer, McLachlau, de Selys, 

 Scudder, Van Volxem and others. 



2 A single species, doubtfully referred by Heer to the 

 latter suborder, has, however, been found in the Lias of 

 Schambelen. 



8 The only Coleoptera known to me are Curculioides 

 Anslicii Buckl., from Coalbrook Dale, Troxites German 

 Goldenb., from Altenwald, and the borings of a Hylesinus 

 described by Brongniart as occurring in petrified wood from 



MEMOIRS BOST. SOC. NAT. HIST. VOL. III. 



the carboniferous limestones of Autun. Geinitz also de- 

 scribes borings of a larger beetle in fossil wood from the 

 Saxon coal measures to which Fric gives the name of 

 Xyloryctes planus; and Sternberg others from Bohemia of 

 a doubtful character, which Fric calls Xyl. seplarius. ' 'urc. 

 l'n stvicii Buckl. has been shown to be an Arachnid. 



The only Hemiptera from these lowest rocks are Fulgora 

 Ebersi Dohrn and Fulgorina Ktieveri Goldenb., from 

 Saarbriicken, and Macrophlebium Hollebeni Goldenb., from 

 Manebach ; besides Fulgorina lebachensis Goldenb., from 

 the Permian. Eugereon Boeckingi Dohrn, cannot be classed 

 here, as will appear further on. 



