278 BULLETIN OF THE ' 



description any character not agi'eeinj:f with the Odonata, except the du- 

 bious cells of the front margin, and these are nowhere mentioned in the 

 description. 



The small portion of the reverse, which I have examined, is a triangular 

 fragment 20 mm. long and 2 to 8 mm. broad. It belongs to a part of the base 

 of the wing, whicli is not preserved in Fig. 8. It does not reach the costal 

 margin, and contains several sectors crossed by a straight vein (sector trigonuli 

 inferior) similar to the arrangement in Isophlebia. The rever.se strongly 

 confirms my determination. This sector is to be found only in Odonata, never 

 in Ephemeridse. The specimen was probably a hind wing. 



Lithentomum Harttii. 



I have examined the type (Fig. 3) of the Boston Society of Natural History. 

 It is very difficult to determine the fragment. A part of the base and of the 

 lower part of the wing lies below (or perhaps above, as some fragments seem 

 to indicate) a Calamites. The base with the stronger triangular basal attach- 

 ment of the wing is seen on the otlier side of the plant. There are strong indi- 

 cations that the other wing of the same side lies below this wing, and the 

 margin of it a little before the margin of the fragment that is figured. A deeper 

 linear impression on the opposite side of the Calamites makes it probable that 

 here the upper wing of the other side of the insect may be in the slab. The 

 fragment is 36 mm. long; the breadth (at 24 mm. from the base) is 15 mm., 

 where a very short portion of the hind border is to be seen. Farther off the 

 bind border is broken, so that at 32 mm. from the base only 9 nnn. of the 

 breadth is preserved. The veins are very faint, and in some jiarts the veins of 

 the underlying wing make them somewhat uncertain. In the costal space 

 some very weak oblique cross veins are visible. What is to be seen of the 

 longitudinal veins, of their forms, and of some oblong cells between them, 

 which are contracted at bpth ends, reminds us of the venation of the actually 

 living Sialids, and more of the Chauliodes type. The base of tlie externo- 

 median shows above and below an arrangement which is to be found in the 

 wing of Chauliodes. The other parts of the venation give no help for a 

 nearer determination. The paucity of the off-shoots of the scapular branch is 

 by no means exceptional, as the author believes; the living Chauliodes pos- 

 se.sses only one, the character claimed by the author for his new family Ci'oni- 

 cosialina. Therefore I do not understand why we should consider the fossil 

 species as a precursor of the Sialina, before a better knowledge of the species 

 supports this suggestion. Fig. 3 is less accurate than the other figures. 



Homothetus fossilis. 



This interesting fragment, of which I have not seen tlie type, shows near the 

 tip of the wing some irregularities of the venation, as if a fragment of another 

 wing lay above or beneath the specimen. The author declares it to belong to 



