362 rEOCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



Genus SIPHONOPHORA Brandt 



SIPHONOPHORA LIMITARE, new species 



Two males, one the type (U.S.N.M. milliped no. 1159), and three 

 females collected at Brownsville, Tex. (without date), by H. S. 

 Barber, of the U. S. Bureau of Entomology and Plant Quarantine. 



Diagnosis. — The combination of characters exhibited by the head, 

 i. e., the rounded sides, short beak, and the short and stout antennae, 

 has not been reported for any other Central American or Mexican 

 species of this genus. The broad, thin, truncated terminal joint of 

 the anterior gonopods also seems very distinctive of this species. 



Description. — Body slender; the largest specimen, a female, is 16 

 mm long and 0.7 mm wide and has 80 segments; the other two 

 females have 44 and 03 segments ; the male type has 78 segments, and 

 the other male 68. Dorsal surface of body invested with very short, 

 erect pubescence. 



Head short, subglobose, the sides slightly rounded (fig. 32, a). 

 Beak a little over half the length of rest of head, very slightly de- 

 curved, and with a cluster of long hairs at base on under side. An- 

 tennae short and stout, not so long as head, and with tip of beak 

 reaching opposite middle of sixth joint (fig. 32, h). 



First segment with anterior margin evenly and shallowly emar- 

 ginate. Segments 2, 3, and 4 shorter than ensuing ones and much 

 more convex longitudinally. Repugnatorial pores large and opening 

 from slight conic elevations. 



Anterior gonopods short and crassate, subglobose, coarsely hairy, 

 the joints indistinct. What appears to be the terminal joint is short, 

 broad, and thin, and the apex is transversely and obliquely trun- 

 cated. Posterior gonopods long and slender, extending forward be- 

 tween anterior gonopods and exceeding their tips; apical joint 

 longer than other joints. 



Remarks. — This is the first record of a species of this genus in the 

 United States, although species of closely related genera are known 

 from Arizona and California. Partly on the basis of finding, in a 

 few especially favored localities in south Texas, a number of deli- 

 cate, humus-inhabiting arthropods and two millipeds associated with 

 tropical forms, it has been inferred that in former times extensive 

 forests were present in the region and allowed a general distribution 

 of humus animals, which later were restricted and isolated by chang- 

 ing conditions.^ The discovery of a species of Siphonophora in the 



'^ Cook, O. F., Cbanse of vegetation on tlic south Texas prairies. U. S. Bur. Plant 

 Industry Giro. 14, 1908. 



Cook, O. P., Notes on tlie distribution of millipeds in southern Texas, with descriptions 

 of new genera and species from Texas, Arizona, Mexico, and Costa Rica. Proc. U. S. 

 Nat. Mus., vol. 40, pp. 147-167. 1911. 



