44 bulletin: museum of comparative zoology. 



The Dolomites. — A rock of an extremely compact nature and homoge- 

 neous in texture. Generally it is white or yellowish brown in color. It 

 is apparently non-fossiliferous. It weathers to that bluish color on the 

 escarpment faces so admirably seen in many Silurian limestones. The 

 lillipiitian mountain-range structure is well exemplified on weathered 

 surfaces. — Specific gravity, 2.71. 



The Shelly Limestone of the Main Island. — In patches it is white in 

 color, but generally preserves a tint varying from light yellow to rich 

 brown or red. In the softer sandy beds there is no fracture, as the rock 

 crumbles beneath the finger, but in the sparely fossiliferous beds the 

 fracture is flat. This freestone exhibits a wonderful evenness of texture, 

 consisting of small calcareous sand particles compacted into solid rock. 

 In other beds, again, although area for area there is a general uniformity 

 of appearance, still in any small individual block there are vast deviations 

 from any common standard of homogeneity that may be set up. Con- 

 cretions occur which, when struck with the hammer, emit spai'ks, and 

 are exceedingly difficult to break, while round them may be clustered 

 roulettes of foramens lying in loosely cemented sand. These petri- 

 factions have conchoidal fractures, and are exceedingly compact and 

 minute in structure. A cliff face may present the curious effect of a 

 soft exposure, dotted over with hard sub-cylindrical protuberances stand- 

 ing out five or six inches from the vertical face. All the beds are 

 extremely porous. A small patch of coral reef has been sandwiched 

 in between a bed of greasy clay and a fine-grained limestone. From 

 a short distance the cliffs with their uniform and persistent lines of 

 stratification, their warm brown and yellow tints, and their "rock- 

 shelter" development, have striking similarity to some of the Triassic 

 arenaceous sandstones of the. Sydney district, but the age of the Fiji 

 rocks is of course very different, being probably Tertiary. 



What has just been said concerning the Thuvu-Singatoka area is 

 true also for the calcareous beds near Suva. Here also the rock, 

 considered in belts, is fairly homogeneous. 



Calcareous Rock <i„<l Coral Rock passing into Soapslone. — On the west 

 side of Suva harbor beds occur that pass gradually from soapstone to a 

 sandy limestone rock. There is no sharp line of demarcation. The one 

 shades insensibly into the other. Exteriorly it often pi-esents a rough 

 and hard appearance, but breaks down under the hammer into a sandy 

 clay rock. At various times large serrated Carcharadon teeth, carapaces 

 and plastra of turtles have been unearthed from the Suva stone. The 

 rock is rarely cavernous and contains few fossils. 



