from Japan and the Indian Ocean. 91 



(' Ingolf Ech. pi. xii. figs. 2, 3). The spicules are rather 

 smnll, irregular, fenestrate phites, arranged in the lower part 

 of the tube-foot in two distinct series; there is no sucking- 

 disk and no prolongations from the spicules into the partition- 

 wall of the foot {Ph. bursarium) . The abactinal tube-feet 

 are almost quite destitute of spicules. 



Tlie primary abactinal spines, both ambulacral and inter- 

 ambulac]-al, are very characteristic (PI. V. figs. 15, 16). in. 

 the lower part they are quite smooth ; some way out several 

 spread thorns appear, and these soon become arranged in very 

 distinct and rather distant whorls, the part between the 

 whorls being quite smooth. All these spines unfortunately 

 are broken, so that it is impossible to give any idea of their 

 lengtli or of the structure of the point. The spines are 

 straight. These spines afford the most prominent character 

 of the species. In Ph. hursarium the primary abactinal spines 

 are curved and smooth, in placenta straight and smooth. 

 The secondary spines (PI. V. fig. 17) are thorny in their 

 whole length, but ^e thorns are not arranged in whorls. 

 The spines of the actinal side are like those of the other 

 species. 



The shape of the test is the same as in placenta, but it is 

 more delicate and fragile than in that species. The specimens 

 before me are bleached, only the skin-bag of the primary 

 actinal spines is faintly violet. 



This species is evidently nearly related to Ph. placenta and 

 hursarium^ whereas Ph. allernans, de Meijere, on account of 

 the different arrangement of the tubercles and its pedicellarItT3 

 being provided with a keel, stands more apart. De Meijere 

 ('Siboga' Ech. p. 32) says respecting this species: — '' Es 

 scheint mir einekleine Erweiterung der beziiglichen Diagnose 

 [of the genus Phonnosoma'] mehr erwunscht, als dass icli fur 

 diese Art gleicli wieder cine neue Gattung errichten wLirde.''^ 

 I quite agree with de Meijere that the species described by 

 him ought to be referred to the genus Phrnnosoma, for the 

 present at least. If, on the other hand, there should prove to 

 be other species more nearly related to it than to the other 

 group of species, it would probably be justifiable to create a 

 new genus for them. The genus Phormosoma, indeed, seems 

 to me so different from the other Echinotiiurids that i should 

 not be surprised if it eventually proved to form a separate 

 subfamily of the Echinotiiurids. 



De Meijere (' ISiboga' Ech. p. 250) finds it a drawback to 

 the new classification given by me in the ' Ingolf Echinoidea 

 that new species do not always suit the diagnoses of the 

 genera given there, as, e. g., Phormosoma allernans. May not 



