Coelopleurus longicollis A. Agassiz & H.L. Clark

Family: Arbaciidae

Order: Arbacioida

Locality: Philippines

Dimensions: 27 x 15 mm

When I got this specimen I thought to have a Coelopleurus maillardi. But Dr. Simon Coppard , a specialist for the order Arbacioida from the National Historic Museum, London, informed me, that it is really Coelopleurus longicollis. I feel free to post his remark as follows:

This is the test of C. longicollis. This species has very similar marking on the interambulacra to C. granulatus, however, the test of C. longicollis is more flattened adapically and lacks the very distinctive granulation all over the test which form the attachment points for triphylous pedicellariae in life. The 5 periproctal plates are slightly unusual but not unheard of. Spine and pedicellariae structure easily distinguish these species.