COKOLAMPAS SIGSBEI. 51 
resentative of the Conoclypei, with its central apex and characteristic ambu- 
lacra, by the name Conolampas, until we know more of the structure of the 
interior of the actinostonie of the Cretaceous genus Phylloclypeus of De 
Loriol, as well as of the species of Echinohmipas with high test, to which 
this species of Conolampas may perhaps be more closely related than now 
appears. Cotteau has figured such a species of Echinolampas {E. scmiorhis, 
Guppy) from the Eocene of St. Barthelemy, and he likewise calls attention 
to its resemblance to several species of Conoclypus. 
As I have already stated in the Preliminary Report of the Blake Echini 
(Bull. M. C. Z., v.. No. 9, p. 191), I described in the Revision of the Echini, 
and figured on PI. XVI. of that work, several stages of the young of Cono- 
lampas ( Comcltjjnis Sif/shei A. Ag.) as the young of Echinolampas. I had not 
at that time dredged Conolampas, and was thus misled, by the examination 
I had made of only a few 3'oung stages either of Echinolampas or of Cono- 
lampas, to consider them all as belonging to the same genus. 
Additional young specimens of Echinolampas and of Conolampas having 
been obtained in the Caribbean by the Blake, I am now able to rectify my 
error, and, by referring to the figures given on Plate XVI. of the Revision, 
to indicate those which belong to Echinolampas, and those which represent 
young stages of Conolampas. 
It will be seen that in corresponding stages of growth of these two genera 
we find in one case, in young specimens of Echinolampas, already the first 
trace of the peculiar petaloid development of the ambulacra characteristic 
of this species (PI. XVI. Figs. G, 7, Rev. Echini) ; while in tlie corresponding 
young stages of Conolampas (PI. XVI. Figs. 4, 11, 12, Rev. Ecliini) the 
ambulacra have the characteristic structure of the genus. To recapitulate, 
Figs. 6, 7, 17, 18, 19, 21, of Plate XVI. of the Revision, belong to Echino- 
lampas, while Figs. 1-5 and 8-16 of the same plate belong to the 3'Oung 
stages of Conolampas. 
The Pygaster or Echinoconus* stage, if I may so call it, of both Echino- 
lampas and Conolampas, appears to be a most characteristic stage of these 
genera, and it is possible that the recent species mentioned by Loven as 
Pi/fjasferrelichis,m.VLj after all only be a young stage either of Echinolampas 
or of Conolampas. This is very probable judging from the size of Loven's 
specimen, 3 mm. in diameter, and from its origin, the Virgin Islands. 
* See the excellent figures of a fine series of Echinoconus given by Cotteau in Bull. Soc. ties Scien. Hist. 
et Nat. de I'Vonne, (2,) IV., 1S81, PI. I. 
