URBICOLA COMMA. 165 



a distinct notch in advance of the preapical tooth ; posterior 

 border of clasp subangulated, scarcely produced beyond the 

 apical tooth . . .. .. .. .. .. .. ..6. 



5 . Apical teeth of clasp less closely approximated, readily dis- 

 tinguishable ; anterior inner edge of apical tooth produced as 

 a sharply and distinctly denticulate lamina ; no distinct notch 

 in advance of the preapical tooth ; posterior border of clasp 

 rounded, produced considerably beyond the apical tooth . . 7. 

 6. Apical teeth of clasp very closely crowded together, the 

 preapical slightly the longer ; lamina continuing the 

 inner anterior edge of the apical tooth moderately 

 high . . . . . . . . . . . . . . Colorado. 



6. Apical teeth of clasp not so closely crowded together, and 

 of equal length ; lamina continuing the inner anterior 

 edge of the apical tootb, very low and inconspicuous manitoba. 

 7. Posterior margin of clasp smooth, rounded ; inner anterior edge 

 of apical tooth forming a denticulate lamina, more nearly 

 transverse than horizontal in its relation to the clasp, the 

 largest denticulations above, the lamina terminating gradu- 

 ally, opposite the posterior border of the preapical tooth . . juba. 

 7. Posterior margin of clasp ragged and irregular; inner anterior 

 edge of apical tooth forming a denticulate lamina, more 

 nearly horizontal than transverse in its relation to the clasp, 

 the denticulations as large below as above, the lamina falling 

 abruptly off at its anterior extremity opposite the anterior 

 border of the preapical tooth . . . . . . . . . . comma. 



Speyer, on confessedly slender material, writes (Can. Ent., xv., 

 pp. 141 et acq.) an interesting paper on the American forms of Urbicola 

 comma. With specimens of nevada, manitoba, Colorado, and juba before 

 him, as well as a supply of comma from northern and middle Europe, 

 and eastern Asia, including Amurland, Amasia, and Lebanon from 

 Staudinger, and comprising many interesting specimens differing very 

 materially from the central European type, he notes that none were 

 actually identical with an American form, although occasionally an 

 approach occurs, but adds that for the most part, their variations from the 

 central European type lie in a different direction than toward the 

 American forms. They afford, however, ample evidence of the great varia- 

 bility of the species under the pressure of various climatic and other 

 external conditions. In the structure of the body, and, in the form 

 of the antennas, palpi and legs, apparently no difference exists between 

 Scudder's species mentioned above and U. comma. The coloration of the 

 underside varies considerably, however, but offers no available character- 

 istics for the separation of individual forms ; sometimes the secondaries 

 are distinctly veined, whilst, in connection with the bright or dull colours 

 of the square spots, their extraordinary variation in size, the presence or 

 absence of their black border, no exact forms can be denned, as all these 

 pass into each other by imperceptible gradations. Having separated juba 

 as a well-marked form, he lumps manitoba, Colorado, and nevada to- 

 gether to compare with comma, and states that, in the size, shape, 

 colour, and markings of the upperside of the wings, as well as in the form 

 of the discal stigma, he finds no variation from comma, but adds that 

 none of the compared American insects entirely agree with European and 

 Asiatic comma in the shape and arrangement of the white spots on the 

 underside of the secondaries. He says that " the interrupted row of 

 spots beyond the middle of the secondaries in typical comma consists, as is 

 well-known, of six more or less quadrangular spots, separated by the 

 nervules, two of which, often somewhat larger and oblong in shape,. 



