RARDWICK&S SCIENCE-GOSSIP. 



49 



NOTES ON GEOGRAPHICAL DISTRIBUTION. 



By T. D. A. COCKERELL. 



[Continued from page 26.] 



S regards the avi- 

 fauna of the Colo- 

 rado region, the 

 Mexican and Ame- 

 rican element is 

 much more in the 

 ascendant, and up 

 to the present I 

 have only observed 

 four which are spe- 

 cifically identical 

 with those in the 

 British list, and of 

 these Ageltzus fhoz- 

 niceus and Ceryk 

 alcyon, are only 

 occasional and cer- 

 tainly not native in 

 Britain, while Pica 

 rustica is repre- 

 sented by the va- 

 riety Hudsonica only, and Anas boscas alone is quite 

 identical with a native British bird. 



At present I have only two Colorado Crustacea on 

 record, and of these Gamm&rus robustus is allied to 

 our English G. pulex. 



The Arachnida have not yet been worked out, but 

 they have a decidedly European stamp, and most 

 belong to English genera ; the same may be said of 

 the Myriapoda, the genera Julus, Lithobius and 

 Geophilus having abundant species closely allied to 

 their British representatives. 



The Coleoptera, with certain conspicuous excep- 

 tions, are very like the British species, such genera 

 as Amara, Bembidium, Cicindela, Pterostichus, 

 Coccinella, Aphodius, &c., being well represented, 

 while a Pcederus, very like littoralis, is common in 

 certain districts, and I have found European-looking 

 species of Meloe and Quedius. 



Many of the Hymenoptera are peculiar, yet there 

 No. 279. — March 1888. 



are species of Bombus, Vespa, Odynerus, Chrysis, 

 &c, resembling British forms. 



The Neuroptera are to a great extent European in 

 general character. 



The Lepidoptera are also many of them of Euro- 

 pean type, an Alucita resembling polydactyla (hexa- 

 dactyla) is frequent on windows, and many other 

 European genera abound. Of the sixty Rhopalocera 

 I have on record, as inhabiting Colorado, only two, 

 Vanessa antiopa and Dana'is plexippus, have been 

 taken in England, and we know the last to be a 

 recent introduction, but forty-nine belong to British 

 genera, and Picris oleracea represents P. napi, 

 modified by changed conditions, as does Vanessa 

 milbertii, V. urticce, and several others are closely 

 allied to European species. 



The Diptera are similarly for the most part of 

 British genera, Tabanus, Tipula, Lucilia, and Muxa 

 being abundant, and among the Hemiptera we find 

 representatives of such genera as Leptocoris, Lygams, 

 Miris, Calocoris, Notonecta, Corixa, Cimex, Cicada 

 (5 species) and Jassus. 



The only two leeches' I have note of belong to the 

 genera Aulostomum and Clepsine ; earthworms 

 (Lumbricus) are rare, I am told that a few exist in 

 Wet Mountain Valley, but I have not been able to 

 secure an example. 



The flowering plants of Colorado have been ably 

 described by Dr. J. M. Coulter, and present many 

 features of interest. 



In the RanunculaceEe all the genera are British, as 

 well as the following species :—Myosurus minimus, 

 Ranunculus flammu la (represented by var. reptans), 

 R. sceleratus, and R. trichophyUus. The only species 

 of Papaver is P. nudicaule. Among the Cruciferaj 

 are Draba incana, var. confusa, Cardamine hirsuta, 

 Erysimum cheiranthoides, Nasturtium palustre, N. 

 officinale (but this is an introduction, it has been found 

 near Denver, and I found it on Saguache Creek, 

 above Rock Cliff), Camclina sativa, and Lepidium 



D 



