10 
CATALOGUE OF ECHINXDA. 
Hab. Australia. 
a , b. Without spine. Australia. 
c, d , e. Covered with spines. 
** Genital 'pores 5, on the sides of the central madreporiform 
plate , between the apices of the ambulacra. 
f Vent transverse. 
4. Laganum depressum. 
Body oblong, sub-decagonal ; front edges high, rounded ; 
hinder side depressed, obliquely flattened, and with a thinner 
edge ; ambulacral bands often ending in two or three additional 
pores ; ovarial pores five. 
Lagana depressa, Lesson , Mus. Paris. 
Laganum depressum, Agassiz , Mon. Scuielle , ii. 110, t. 23, f. 1-7, 
149 ; Agassiz Desor , 1. c. 132. 
L. reflexum, Agassiz, , Mon. Scut. t. 26, f. 1-3 ? 
L. tenuissimum, A gassiz , Mon. Scut. t. 26, f. 46 ? 
Hab. Indian Ocean. 
a. Large, covered with spines. Australia, Darnley Island ^ 
Presented by J. B. Jukes, Esq. 
b, c. Large and small. Darnley Island. Presented by the 
Earl of Derby. 
d, Large, without spines. 
e, f,g. Smaller, covered spines. 
h. Without spines, more depressed, ambulacral petals 
rather narrower. Siquigor. Mr. Cuming’s Collection. 
i. Without spines. 
Yar. 1. % Under-side of shell depressed, flattened ; vent large, 
transverse ; ambulacra rather wider, ovate, lanceolate. 
a. Without spines. 
b. Without spines. Mauritius. Presented by Lady Frances 
Cole. 
Yar. 2. Middle of back more elevated. 
Lagana. tonganensis, Quoy 8$ Gaimard , Mus. Paris. 
Laganum tonganense, Agassiz . Mon. Scutelle, 114, f. 26, f. 7-19, 
150 ; Agassiz Desor , 1. c. 132. 
Hab. Tonga. 
o. Laganum attenuatum. 
Nearly allied to L. tonganense , but depressed round the am- 
bulacra ; differs from L. ellipticum in the more angular form, 
and circular vent ; hinder edge bevelled ; mouth small. 
Laganum attenuatum, Agassiz Desor, 1. c. 132. 
Hab. Red Sea. Semifossil. 
a, b, c. Semifossil ? Red Sea. Presented by Sir J. G. 
Wilkinson. 
