LOVENIA CORDIFORMIS. 19 



criim is thickly covered by secondaries and small niiliaries. The anterior 

 pair of petals, although shorter than the posterior, extends nearer the edge 

 of the test. 



In small specimens, not measuring more than 4.5""", the test is more cylin- 

 drical ; the ambulacra are not yet petaloid, but, as in young Spatangus, the 

 poriferous zones ai'e diverging, composed of simple disconnected (figured on 

 PL XI^. f. 19, Rev. Ech.) pairs of pores; the abactinal part of the an- 

 terior zone of the anterior lateral ambulacra is already obliterated. The 

 posterior pair of petals are first formed, by the spreading of the zones, due to 

 the increase in width of the interporiferous space. This occurs while the 

 pores are still simple, and somewhat later in specimens about a third (G'""' ) 

 the length of tlie one figured ; the pores of the petals separate and become 

 conjugated, and form the petaloid portion of the ambulacra. 



Off Juan Fernandez ; 65 fathoms. 



Lovenia cordiformis 



! Locenki cordiformis LuTli. MS., 1872, in A. A(i , Bull. M. C. Z , III. 



A broken specimen of this species was presented to the Hassler Expedition 

 by Mrs. William Knapp of San Diego ; it enables me to add a few points to 

 the imperfect description given in the Revision of the Echini. This species 

 is, when compared with L. elongata, remarkrJjle for its shallow and narrow 

 anterior ambulacral groove, the elongate internal fasciole, the large size and 

 proximity of the genital openings, l)ut more especially for the narrow field 

 of large secondary tubercles flanking the apical part of the odd ambulacrum 

 between it and the internal fasciole. The internal pouches of the tubercles 

 in the lateral interambulacra are much smaller and more closely packed than 

 in specimens of the same size of L. elongata. This species is more closely 

 allied to L. elongata than to L. subcarinata, to judge from the fragments of 

 the posterior extremity in my possession. 



San Diego ; California. 



Agassizia excentrica 



\Agassida excentrica A. Ac, 1869, Bull. M. C. Z., I. p. 27G. 



On PI. XIV. f. 9-12 of the Revision of the Echini, I identified as the 

 young of Agassizia a small Spatangoid ; tills was done with considerable 

 hesitation, on account of the extreme flatness of the test, differing from 



