NEOLAMPAS EOSTELLATA. 45 
in two specimens, one of which measured probably 7-8 mm. in length, the 
other from 10 to 11 mm. The interambulacral spines of the bonrrelets are 
slender and longer than those of the tubercles of corresponding size in other 
parts of the test. The somewhat distant primary radioles, are short, sharp, 
slender, and the intertubercular space of the whole test is thickly covered by 
secondary tubercles, carrying small, slender, straight radioles, usually having 
a slight cup-shaped extremity, which have been well figured by Thomson in 
the Echini of the Porcupine Expedition ; he has also figured the pedicellarite 
characteristic of this species. The principal large pedicellaria3 are more 
closely allied by their structure to the Clypeastroid than to the Spatangoid 
types ; in addition to these, there are also in the ambulacral areas more 
numerous pedicellarioa with short stout stems, quite similar to the secondary 
radioles but somewhat more slender, carrying a small trifid head set closely 
upon the cup-shaped extremity of the stalk. Minute long-stemmed, small- 
headed pedicellarioa are found near the actinostome in the ambulacral and 
interambulacral areas. 
As the test increases in size its outline becomes more angular, the posterior 
extremity more elevated, and the Spatangoid features of the genus more ap- 
parent. There is, however, even in the largest specimen collected, no trace 
of petaloid ambulacra on the abactinal surface; the ambulacra retain as far 
as we know their simple embryonic structure. The apical system is compact, 
the genital openings are large, the left anterior and posterior genitals are 
atrophied. This was not the case either in the specimens collected by 
Thomson or in those previously dredged off Florida, in which the left 
anterior genital pore was wanting, in addition to the odd posterior one. In 
a specimen measuring 10 mm. in length there are two or three madreporic 
openings in the space between the genital openings. In Thomson's speci- 
mens, which are larger than any I have dredged, there are two such 
openings. I was unable to distinguish the line of sutures between the 
different genital plates. When covered with spines, the genital openings 
are protected by long secondary spines, and genital tubes are seen to 
project through the large openings beyond the level of the spines. Two 
or three, and sometimes four, sphseridia are found near the actinostome 
in each ambulacral area. 
