12 5 ECHINOIDEA. I. 



That this form is widely different from Toxocidaris tuberctdatus is evident from the characters 

 mentioned here; on the other hand the globiferous pedicellarise show that it is rather closely allied to 

 Strongylocentrotus. Bnt the peculiar spicules and the petaloid pore areas characterizes it sufficiently 

 as a separate genus, which keeps, of course, the name of Anthocidaris. L-iitken (loc. cit) regards it 

 as identical with Echinus homalostoma Valenc; I do not know whether this is correct, but it is so far 

 of no consequence, as this species will, at all events, get the name of Anthocidaris homalostoma. I 

 suppose that this species has hitherto been confounded with Toxocidaris tuberculatum^ which it resem- 

 bles to some degree, and which is also said to occur at Japan. T. tuberctdatus, however, is indigenous 

 in the Australian seas, and until renewed examinations have corroborated its occurrence at Japan, I 

 must suppose a confounding with A. homalostoma to have taken place. As to habitus A. homalostoma 

 is very similar to Pseudoccntrotus depressus, which latter has also petaloid ambulacra; but its colour 

 is (always?) brownish red, and it is somewhat more flattened. The examination of pedicellarise and 

 spicules will immediately show them to be two widely different forms. 



Where the species Sir. mexicamis, nudus, and glohdosus are to be referred, cannot be seen 

 from the existing descriptions. The other species referred to Strongylocentrotus thus prove to belong 

 to no fewer than 6 different genera: Strongylocentrotus, Pseudoccntrotus, Loxcchinus, Paraccntrotns, 

 Toxocidaris, and Anthocidaris, and it may perhaps even be necessary to divide the first one into two 

 genera. And these genera are excellently characterized, and so far from being closely allied, that they 

 are to be grouped into three different families. We can scarcely wish for a more striking proof of the 

 insufficiency of the characters that are taken only from the test and the spines. 



Stomopneustes variolaris (Lamk.). Of this very peculiar form I am able to give some new 



informations; I have not, however, had material sufficient for clearing up everything that might be 



wished for. — A primary tubercle is only found on every fourth or fifth ambulacral plate; each of 



these large tubercles spreads over more plates — but it is difficult to decide over how many, as no 



boundary lines are seen between the plates; it may, however, be seen from the pores that the fact is 



so, as more arcs are found opposite to each tubercle. Two ocular plates reach to the periproct. The 



buccal membrane contains numerous lengthened, fine fenestrated plates, of which a few are a little 



complicate and carry pedicellarise. Small spines are found on the buccal plates. The gills contain 



numerous, mostly three-radiate spicules (PL XVII. Fig. 13), but not the common irregular fenestrated 



plates. The globiferous pedicellarise are of a quite unique form. There is no end-tooth, but the blade 



ends truueately with a long tooth in each corner (PI. XVII. Fig. 17), sometimes two teeth on one side, 



or that on the one side a little below the corner. These teeth have no poison canal, and upon the 



whole no poison gland seems to be found (I have not, however, been able to ascertain this fact with 



full certainty). The blade is open, rather flat, the apophysis ends abruptly without any widening 



above. There is no neck, and the stalk is very short and compact. This very peculiar, large, and 



powerful form of pedicellarise is, unfortunately, very scarce; in the two specimens I have examined, 



I have only been able to find one in each specimen, placed in one of the interambulacral furrows 



near the ambitus. Besides another, smaller form of globiferous pedicellarise seems to be found, with 



end-tooth and 1 — 1 lateral tooth, very similar to those of Paracoitrotus lividus; but I have not been 



able to make quite sure of this fact. The tridentate pedicellarise are distinguished by the apophysis 



