OF SANTO DOMINGO. j 157 



There is but little to describe in the sixty miles of valley between Monte Cristi 

 and Santiago, The sandstone strata — light gray, semi-calcareous, and containing 

 03'Sters and a few corals — in the hills back of Monte Cristi have been already men- 

 tioned. After crossing the trifling elevation caused by these beds, the road runs 

 along a clay flat in the river bottom, occasionally passing the point of a low hill 

 made up of the sandy beds in the yellow shale. About two miles west of Guayubin, 

 little exposures in the i"oad show the yellowish shale, with a few yellow sandy clay 

 beds, nearly horizontal and with an abundance of fossils. I collected several species 

 of Pleurotoma, Fusus, Watica, Conus, Cassis, OUva, Septaria, Area, Nucula and 

 corals identical with species from the blue shale of the Samba Hills ; and three miles 

 east of the town, where a little i-oad-cutting of a couple of feet deep showed an 

 exposure, I found all of the same species in abundance. The great Area patricia 

 was especially abundant ; and this fossil, with the oyster and spondylus, with their 

 thick nearly indestructible shells, resists the disintegration which destroys the smaller 

 species, and lie scattered over the surface or mixed with the soil at a hundred points 

 along the valley. But here it was found in place tind in good condition, associated 

 with little flakes and scales of imperfectly crystallized selenite. The selenite is doubt- 

 less derived from the decomposition of shells, and where it occurs I have usually 

 noticed that fossils disappear entirely. Here they abound, though some are coated 

 with glistening crystals of the mineral, showing the change actuall}" taking place. 

 East of this point very few fossils were found ; but this is easily accounted 

 for by the fact that the debris from the mountains covers the valley on its northern 

 margin, while the river deposit hides nearly everything near its shores. 



About Hatillo de la Palma the bottom is so low that at times the I'iver overflows 

 its banks. The soil is consequently marshy but exceedingly rich, and the forest- 

 gi'owth is like an island in the midst of the barren-looking acacia and cactus plains. 

 But this does not continue very far, and soon the traveller emerges in the open sandy 

 ground again. On approaching Guayacanes, the cactus becomes more numerous and 

 the acacia-trees more dense until when the little village is reached. But a single 

 house of its dozen or twenty is visible from the road. The remainder aie scattered 

 over a space of a mile, and usually one or two hundi-ed yards from the I'oad. The 

 resemblance of this region to the arid plains of Lower California is vei'v striking. 

 The same dry soil covered with a scant}^ carpet of grass, the same low, sti-aggling- 

 limbed, open-foliaged acacia-trees : the same tall columnar cactus, with its under- 

 growth o{ ojnmtias ; even the same cloudless sky, make the likeness complete. Xear 

 the cemetery, about three miles east of Guayacanes, a little dry Avater-course shows 

 A. p. s. — VOL. XV. 2isr. 



