ECHINOIDEA 309 



Mediterranean, the Moroccan coast, the Canaries, and Azores. 

 The bathymetrical distribution is 0-30 m. 



II. Family Toxopneustid^ 



Test without depressions or pits ; tubercles smooth. Am- 

 bulacral plates with three or more pore pairs (oligoporous or poly- 

 porous). Gill-cuts sharp and deep. Globiferous pedicellarise 

 without lateral teeth, the outer part of the valves (the blade) a 

 closed tube ; the head attached directly, without a neck, to the 

 end of the stalk. Usually mucous glands are found on the stalk 

 (Fig. 179, 1). Dumbbell-shaped spicules, or at least spicules with 

 the ends thickened, in the skin of the globiferous pedicellarise 

 (Fig. 179, 3). Spicules of the tube-feet C-shaped or branched. 



The head of the globiferous pedicellarise is not rarely lost, the 

 stalk with its mucous glands remaining ; or the head may be 

 more or less rudimentary or even be not at all developed. Such 

 rudimentary or mutilated globiferous pedicellarise have been 

 regarded as a special sort of organs, the " Globiferse " or the 

 " Cystacanths " ; but there is no doubt that they are globiferous 

 pedicellarise in which the head has been reduced or torn off. 



Only one genus of this family occurs in the British (and 

 European) seas, whereas the family is very richly developed in 

 the Indo-Pacific. 



1. Sphserechinus Desor. 



Test rather closely covered with spines (tubercles) of a 

 uniform size, the primaries being hardly distinguishable. Each 

 ambulacral plate with 4 pore pairs. Buccal membrane with few 

 small but rather thick plates outside the buccal plates. Spicules 

 of globiferous pedicellariae C-shaped, with the end thickened, not 

 typically dumbbell-shaped ; those of the tube-feet C-shaped, 

 with the ends branched. 



Only one species in British (and European) seas, the only 

 species known of this genus. 



1. Sphcer echinus grayiularis (Lamarck). (Fig. 178.) 



(Sjm. Echinus (Toxopneustes) brevispinosus Risso ; Ech. cequituber- 

 culatus Desmoulins ; Sphcerechinus roseus Russo.) 



Test low, but arched, not flattened ; spines short, rather 

 thick ; the larger tubercles arranged in a fairly distinct trans- 

 verse series on each plate, especially at the ambitus. Primary 

 tubercles on all the ambulacral plates. No spines on the buccal 

 plates. Globiferous pedicellariae with rather short valves. 



