Eucidaris tribuloides is another sea urchin that is slated for genome sequencing. It is commonly called the "pencil urchin" because it has a fewer number of very thick spines compared to the purple sea urchin. Images of this species is available here. The taxonomy of this species is collected at the species page of World Register of Marine Species.BioProject PRJNA62465 at NCBI describes 39,800 ''Eucidaris tribuloides'' transcriptome assemblies from 454 reads collected before and after gastrulation. It can be found here. Actual sequences can be found here
Baylor’s data on Strongylocentrotus franciscanus and Allocentrotus fragilis
Sequencing of A.fragilis, S.franciscanus was done in two stages - first time in 2007 and then in 2008. The data files available from Baylor includes both sets. There are types of files from Baylor:
i) Af, Sf directories with the reads (6990661 for Af and 5811973 for Sf).
ii) Qual files for the reads.
iii) Files showing alignment regions between A. Fragilis (or S.franciscanus) and S. purpuratus.iv) Base by base alignment file between Af/Sf and Sp 2.1 genome.
There is a description of the red sea urchin, Strongylocentrotus franciscanus here