14 PSYCHE [February 



AN ABNORMAL SPECIMEN OF BEMBIDIUM SC UDDER/. 



BY ROLAND HAYWARD, MILTON, MASS. 



While examining a number of examples of Bembidimn scudden recently 

 received from Mr. H. F. Wickham from Humboldt Lake. Nev., I noticed a curious 

 monstrosity in a specimen of that species which seems of sufficient interest to 

 publish. 



As is well known the dorsal punctures of the elytra are very constant both in 

 number and position in our numerous species of Bembidium, and afford very use- 

 ful characters for the subdivision of the genus into groups. With few exceptions 

 they are two in number and are situated either on the third interval or the third 

 stria. In two of our groups, one containing Icevigatum, and the other semistriatum 

 and constricticolle, they are placed in irregular rows on all the intervals. In two 

 others they are three in number, being situated on the third stria in that of which 

 rickseckeri is the type, while in the group containing hens/iawi, cntisitnilc, sciidderi 

 and hageni they are on the third interval. 



In the specimen before me there are on the third interval of the left elytron 

 the abnormal number of four punctures, while on that of the right there are three, 

 placed as in normal specimens. On the left elytron the first puncture is in normal 

 position, the second, however, is situated much nearer the base, while between it 

 and the one nearest the apex, which is situated as on the right elytron, is inter- 

 polated an additional puncture, placed nearly midway between the second and 

 fourth, but slightly nearer the latter. A curious fact to be observed is that only 

 the first, second and fourth punctures are setigerous, the third showing no trace of 

 seta. The seta arising from the three dorsal punctures of the right elytron are 

 also distinct. 



Of course the case is a monstrosity only, showing as it does, in a small way, a 

 deviation from bilateral symmetry, but it seems interesting that it should occur in 

 a member of a group in which the normal number of dorsal punctures is in excess 

 of that occurring in the vast majority of our species, and may possibly indicate an 

 inherited tendency toward an increase in their number. 



The group as a whole is confined to the western portions of our country and 

 to Mexico. Only one species, B. consimile, occurs as far east as Nebraska, extend- 

 ing westward to Utah, while henshatvi and sciidderi occur in the region between 

 western Wyoming and California. All three are found, as 1 learn from corre- 

 spondents, on alkaline mud along the shores of saline lakes and ponds. Of the 

 habits of hageni nothing is known. 



