ECHINAEACHNIUS PAEML. 43 
LaganidfB.* Among the specimens I have had occasion to examine I do 
not find any marked diiference due to age in the width of the marginal 
edge which is occupied by the pillars. The structure of the test of the 
flat Clypeastroids shows that they are closely connected with Conoclypus, 
the ambulacra! furrows and the teeth specially showing these groups to 
have an intimate connection. Echinolampas, on the contrary, although 
superficially more closely related, in reality differs more from Conoclypus 
than do the flat Clypeastroids. 
Clype aster Ravenellii A. Ag. 
Stolonoclypus RaveneUii A. Ag. Bull. M. C. Z., I. p. 265, 1869. 
West Florida Bank. 14 fathoius. Yucatan Bank. 84 fatlioms. 
PI. XV\ Figs, i, 3; PL XV\ Fi(js. 1, 
lu -r^f 
Clypeaster subdepressus Ag.4ss. 
Florida, Yucatan Bank, Le.sser Antilles. 84-1952 fathoms. 
For list of Stations, see Bull. M. C. Z., VIII., No. 2, p. 79, 1880. 
P/. xv. 
</-^K^ 
Echinantlius rosaceus Gr-^t. 
Yucatan, Cuba, Lesser Antilles. 14-118 fathoms. 
The specimens dredged by the Blake show the usual differences in the 
comparative height and length of the test. 
/~»t 
Echinarachnius parma Gray. 
< 
Lat. 40° 59' N., Long. 71° 22' 30" W. Lat. 41° 30' N., Long. 66° W. Off Newport. 71-306 
fathoms. 
For list of Stations, see BulL M. C. Z , VIII., No. 2, p. 79, 1880. 
The genus Echinarachnius extends to a greater depth than Mellita. The 
former was very common beyond the 100 fathom line north of New York, 
and on the George's Bank, but to the south it was not found at the same 
depth, nor were any of the species of Mellita, and but one of Encope, 
dredged by the Blake beyond the 100 fathom line in the very districts in 
which these genera are the most typical littoral species. 
* I would refer also to an article on the Laganida; in Ann. and Mag. Nat. Hist., No. 62, for February, 
1883. I do not propose to discuss the statements made by Prof. F. J. Bell. 
