the piipn placed in it on its back. Soil during the pnpal stage iiir.st 

 l)p kept uniformly moist, and mites must be guarded against. 



In the field, pupation takes place usually at a depth of one and 

 one-half to two feet, which is a foot or more deeper than the larva 

 lives, and this going to a lower level is attributed to an instinct on 

 the grub's part to avoid changes of temperature, and disturbances 

 of the soil by plowing, that would take place nearer the surface. Tt 

 seems, however, that it is simply a provision to so place the pupal 

 cell that the inactive pupa will not be crowded and eventually 

 smothered by the penetration of roots into the cell, which would 

 undou])tedly take place near the surface of the soil in a field. Grubs 

 in the tin boxes showed no discomfort at being prevented from pene- 

 trating to a depth in the soil. 



The freshly issued adult (PI. IV, fig. 6) was left in the pupal 

 eell in the box for several days, to observe its changes in color in 

 leaching maturity. In a week's time or less, before the beetle had 

 shown a desire to leave the cell, a round disc of blotting paper was 

 snugly fitted into the box over the earth and cell, and the box was 

 l)uried. with lid removed, under several inches of damp earth in a jar 

 or pot, the earth packed somewhat, and a cover or cage put over 

 the top in order to determine the date of emergence from the soil. 



Species of Porto Rican Melolonthids. 



All five species of Porto Rican ]\Ielolonthids that have been segre- 

 gated and studied are new to science. The four indigenous species 

 of PhyUophaga, or May-beetles, are being described by the author 

 under the names PhyUophaga vundinei, P. portoricensis, P. guani- 

 cana and P. citri, and the single species of Phy talus under the name 

 PJi y talus insularis. 



The characters which distinguish the species are sufficiently marked 

 to readily separate them from allied species occurring on the neigh- 

 boring islands. In the present pa]ier will be given only the morp 

 important characters necessary to distinguish one species from the 

 other. 



As the four species of Phyllophmja fall naturally into two groups, 

 readily distinguishable by size and other gross characters, and as 

 the two species of each group are restricted to well-defined geogra])hic 

 areas on the Island, one can almost with certainty determine the 

 species by tlie locality in which it was collected, knowing the ap- 

 l)earanee of each group. The males of the four species can be sepa- 

 rated by tile clirracters shown in figures 4. 5. (i niid 7, of Plate Y, 



Of) 



