346 



ECHINODERMS OF THE BRITISH ISLES 



2. Pourtalesia Wandeli Mrtsn. (Fig. 207.) 



(Syn. Pourtalesia miranda Hoyle, Kemp ; probably not 

 Pourt. miranda A. Agassiz.) 



Test nearly cylindrical, scarcely widening from in front 

 posteriorly. Under side nearly flat, not swollen ; the dorsal keel 

 formed by the posterior interambulacrum less conspicuous and 

 not forming a prominence above the periproct. The serial 

 arrangement of the larger tubercles in anterior part of test rather 

 more distinct than in the preceding species. Primary spines very 

 long, the largest exceeding two-thirds the length of test. The 

 pedicellariae in the main as in the preceding species, only the 

 rostrate pedicellariae differ in the valves being broader and more 



12 3 4 



Fig. 207. — Pourtalesia Wandeli. 1. Specimen with the spines preserved ; 

 dorsal side. 2-4. Naked test, from below (1), from above (2), and in 

 side view (3). Slightly reduced. (After Th. Mortensen, " Ingolf " 

 Ech., ii.) 



densely serrate at the point (Fig. 206, 1). Colour in life dark 

 violet. Largest size recorded, 53 mm. length. 



Biology and development unknown. 



From the British seas this species has only been recorded by 

 Agassiz, under the name of Pourtalesia miranda, from off Rockall, 

 56° 44' N., 12° 52' W., 2185 m. (" Porcupine ") ; it would, 

 however, seem most probable that the specimen from the 

 " Porcupine " was really Pourt. Wandeli. The species is other- 

 wise distributed over the Northern Atlantic from off the Faroes 

 to the Davis Strait and the West Indies. Bathymetrical dis- 

 tribution, 1580-3230 m.i 



1 H. L. Clark has recently declared Pourtalesia Wandeli identical with 

 the West Indian P. miranda A. Agass., because some specimens from the 

 West Indies identified by A. Agassiz as Pourt. miranda are indistinguishable 



