510 Mr. T. D. A. Cockerell on new Insects 
ment of the coxa, trochanter, and femur strongly suggestive © 
of that pointed out by me in the case of the Phasmide in my 
communication to the Académie des Sciences of February 15, 
1897 *. I was particularly struck with this on examining 
the last figure referred to, which, however, represents an 
insect much more nearly allied to the Neuroptera than to the 
Orthoptera, since M. Ch. Brongniart has assigned it to the 
former. 
Messrs. Bateson and Brindley, after mentioning numerous 
instances of tetramery in Blattide, conclude that they are to be 
regarded as cases of abrupt vardation (“ variation brusque’’), 
explaining up to a certain point how a species with tetra- 
merous tarsi might be derived, abruptly so to speak, from a 
species with pentamerous tarsi (‘ Materials for the Study of 
Variation,’ 1894, pp. 63 and 415-421). A philosophical 
explanation appears to me much more logical: this consists 
in regarding, on the contrary, these interesting facts as cases 
of atavism, of reversion to an ancestral condition similar to 
that still to be observed in the Locustide t. 
LX.—WNew Insects from Embudo, New Mexico. By T. D. A. 
CoCKERELL, Entomologist of the New Mexico Agricul- 
tural Experiment Station. 
As we ascend the Rio Grande the fauna and flora gradually 
change, southern types giving place to others of a boreal or 
sub-boreal character. ‘The detailed study of the distribution 
of species up and down the banks of the river presents much 
to attract the zoologist or botanist, and the briefest investi- 
gations are repaid by new and interesting results. The 
present writer had recently an opportunity of spending a 
couple of days at Hmbudo, situated on the Rio Grande in 
northern New Mexico, about 800 miles north of Mesilla. 
This locality is in a district never explored by entomologists, 
and it was to be expected that new forms would be found. 
These expectations were not disappointed, and descriptions of 
the novelties are herewith presented. 
Apide. 
At the flowers of igelovea four species of Perdita occurred, 
three of them in considerable numbers. They were as 
follows :— 
* Vide supra, p. 476: “Phenomena of Autotomy in Phasmide 
belonying to the Genera Monandroptera and Rhaphiderus.”’ 
‘+ Cf. A. Giard, ‘Comptes Rendus de la Société de Biologie,’ 1897, 
no. 12, p. 315. 
