EXPLANATION OF THE PLATES AND WOOD-CUTS. 



it quite so wide ; in both these circumstances it approaches to S. lacunosus ; but 

 it is laterally crushed, which may account for the difference. Length \\ inch, 

 width nearly the same, height 10 lines. A magnified view of the surface is given 

 at fig. 23 a. 



Loc. Baboa Hill. 

 Fig. 24. Spatangus elongatus. Elongated, ovate, depressed ; front emarginate ; base 

 convex ; ambulacra concave, with two of the rows of pores nearly central ; apex 

 excentric ; mouth remote from the margin. Length nearly 2^ inches, width If 

 inch, height 1 inch. 



The two posterior ambulacra and the posterior portion of the shell are broken ; 

 the description is therefore incomplete. 



Loc. Baboa Hill. 

 Fig. 25, 25 a. Clypeaster ohlongus. {C scutiformisl Lam.) Oblong, subpentagonal, 

 convex above, concave beneath ; ambulacra very broad, obtuse. The surface mag- 

 nified is shown at fig. 25 a. Length 2f inches, breadth above 2 inches, height 7 fines. 



The specimen is too much mutilated to show the anus. It is more pentagonal 

 than C scutiformis, to which we have before referred it. 



Tertiary Formation. Loc. Between Joongrea and Kotra. 

 Fig. 26, 26 a. Clypeaster depressus. Pentagonal, much depressed ; ambulacra oval ; 

 anus very near the margin. (See fig. 26 a.) Length in the oldest individual about 

 2 inches, breadth rather less, height about i inch. 



This diflfers from C. Laganum in the position of the anus, which in that species 

 is half-way between the mouth and the margin, in the greater size of the papillse, 

 and in being much thinner. 



Tertiary Formation. Loc. Soomrow. 



Plate XXV. 



(Fossils from the Tertiary Formations, Cutch.) 



Fig. \. Serpula ? recta. An oval, free, slightly-waved shelly tube, which we have 

 provisionally called a Serpula, although it is more like the tube of a Teredo ; but 

 it appears to have been formed in loose sand. Diameter f inch. 

 Loc. near Kotra. 

 Fig. 2. Siliquaria Grantii. Spirally striated ; striae crossed by numerous cracks ; 

 fissure composed of a series of oval pores. It differs from the recent S. anguina 

 only in the smallness of the pores which form the fissure. 

 Loc. Borders of the Runn. 

 Fig. 3. Balanus sublcevis. Subcylindrical with curved valves, nearly smooth. Oper- 

 culum ? Diameter 1 inch, height 9 lines. Parasitic upon shells. 

 Loc. Soomrow. 

 Fig. 4. Corhula trigonalis. Trigonal, with the front rounded, gibbose, antiquated ; 

 valves nearly equal, posterior side truncated obliquely with a carina upon each 

 valve, and pointed ; umbones equal, central. Length 6 lines, width 8 lines ; but 

 these proportions vary. 

 Loc. Borders of the Runn. 



