338 CRETACEOUS ECHINODERMATA. 
specimens figured have been returned to their original possessors, or dispersed, 
before Mr. Dixon resolved to abandon the task of describing the fossils of this 
tribe, and requested my assistance. Some of the rarest and most distinct are 
consequently recorded only from the very beautiful drawings in which they are 
represented. 
Genus Ciparis, Lamk. 
1. C. clavigera, Konig. White chalk. 
var. a. communis. (Tab. XXV. fig. 10, 11, 18, 19, 20.) 
var. b. major. Body larger in proportion to the spines. (Tab. XXV. 
fig. 22.) 
var. c. minor. Spines longer than usual in proportion to the body, 
the larger ones more oblong and with fewer serrated ridges. 
In the Museum of the College of Surgeons. Tab. XXV. fig. 14. 
2. C. sceptrifera, Mantell. White chalk. (Tab. XXV. figs. 2, 6, 7.) 
And var. spinis truncatis. (Tab. XXV. fig. 32, 33.) 
3. C. vesiculosa, Goldfuss. White chalk. (Tab. XXV. figs. 1,4, 13, 21 (not 
the spine). 
4. C. serrifera, sp. nov. (Tab. XXIV. figs. 15 tol19; Tab. XXV. fig. 2.) 
Nearly allied to the last species, but differing in several important respects. 
Interambulacra composed of large plates with impressed areole around the 
spiniferous tubercles, four to six in the perpendicular row. Tubercles larger in 
proportion to the areolz than in the last species. Superior plates with indi- 
stinct tubercles, but not so obsolete as in C. vesiculosa. Granulated portion of 
the plates finely grained. The sutures are not impressed. The avenues of pores, 
of which about fourteen correspond to the largest plate, are broader in propor- 
tion to the ambulacra. There is a tubercle between each pore, and an oblong 
transverse ridge between each pair. 
The spines are long, slender, cylindrical, few- (seven or so) ridged; ridges 
coarsely serrated, the interspaces granulated. 
White chalk. 
