PSEUDOMARETIA. 249 



in regard to the composition of the subanal plastron were given at the time the 

 description was written as the importance of this point was not realized. Re-ex- 

 amination of a paratype shows that the plastron is very different from that of 

 M. ovata and very similar to that of M. tuberculata. Seven ambulacral plates 

 on each side enter the plastron but the uppermost (the seventh) barely extends 

 its lower, inner corner within the fascioie, and there are only five large tube-feet 

 on each side. 



Maretia elliptica. 



Bolau, 1874. Arch. f. Naturg., 40, 1, p. 175. 



The unique holotype of this species is from Maiden Island, Tropical Pacific 

 Ocean. It is rather remarkable that the species has not been found elsewhere. 



Maretia elevata. 



Doderlein, 1906. Valdivia Ech., p. 263. 



This species is also known from only a single specimen, which was taken 

 off Witu Land, British East Africa. The most remarkable point, however, is 

 that this specimen was taken at a depth of 385 fms., an unprecedented depth 

 for a Maretia. The individual was only 30.5 mm. long but the -genital pores 

 were fully developed. 



Pseudomaretia. 



Koehler, 1914. Ech. Indian Mus. Spat., p. 107. 

 Type, Maretia alta A. Agassiz, 1863. Proc. Acad. Nat. Sci. Philadelphia, p. 360. 



Plate 146, fig. 24. 



As Koehler (op. cit.) and I (1915. Spolia Zeylanica, 10, p. 91) have recently 

 discussed the type species of this monotypic genus, and as it had already been 

 described and well figured by de Loriol (1883. Mem. Soc. Phys. Hist. Nat. 

 Geneve, 28, no. 8, p. 49-51), there is no occasion to go into details here. I have. 

 however, thought it of interest to figure one of the remarkable pedicellariae of 

 the ventral ambulacra (PI. 146, fig. 24) as Koehler figures the valves separately 

 and a stalk which is somewhat different from those I have seen. As already 

 explained the figures in the Challenger Report, on plate 37, supposed to be 

 of this species, are in reality of Gonimaretia tylota (p. 241). From Mauritius, 

 the range of Pseudomaretia alta extends via Ceylon, where it seems to be common, 

 to the East Indies, Formosa, and southern Japan. 



