No. 2. — Millipeds Collected in Puerto Rico and the Dominican Republic By Dr. P. J. Darlington in 1938 l By H. F. Loomis During the summer of 1938 Dr. P. J. Darlington, of the Museum of Comparative Zoology, Cambridge, Massachusetts, gathered much zoological material in Puerto Rico and the Dominican Republic which included a large number of very interesting millipeds, later sent to me for identification, and now forming the basis for this paper. The Puerto Rican collection of millipeds contained 11 species, and has been exceeded in number only by that of 12 species by Prof. W. M. Wheeler in 1906, and reported on by Silvestri 2 . Four species of the Darlington collection are here described as new, one being made the type of an unusual new genus of the family Stemmiulidae. With these additions, thirty species now have been recorded from Puerto Rico, but the identity of five is in doubt and cannot be settled until much more collecting and study have been done. In the Dominican Republic 35 species were found, and these repre-sent the first extensive collection ever to come from that country, where previously only six species had been known, one of those also being reported from the adjacent Republic of Haiti. In the Darlington collection are six previously described species, one of which was already known from the Dominican Republic, the remaining five being newly discovered there but previously known from Haiti. Twenty-eight of the species, apparently new to science, are described in the following pages, and among them are the types of eight new genera. A single remaining form was represented by inadequate material, impossible to identify specifically. The Dominican portion of the collection is remarkable in the number of new species of Prostemmiulus and Micros pirobol us it contains; and in the many new monotypic genera of the order Merocheta it has been necessary to erect to fit the animals into the current system of classifi-cation. These genera are indicative of a large undiscovered milliped fauna, and future collections in other parts of the country hardly can fail to add species to some of them. Great localization of milliped spe-cies already has been noted in Cuba 3 , and especially in the Republic of Haiti 4 , whence 108 species have been reported. The Dominican Re-public, with double the area of Haiti, remains almost wholly unknown, 1 Published with the aid of a special gift from Mr. George R. Agassiz. 2 Bull. Amer. Mus. Nat. Hist., Vol. 24, pp. 563-578, 1908. 3 Bull. Mus. Comp. Zool., Vol. 82, No. 6, pp. 427-480, 1938. 4 Bull. Mus. Comp. Zool., Vol. 80, No. 1, pp. 3-191, 1936.