Io8 ECHINOIDEA. I. 



with «trois paires de pores obliques*. Now if the two authors had done so consciously, they would 

 certainly have made a remark to the effect that the type specimen had not the six pairs of pores, but 

 only three. Such a remark, as far as I can see, they have not made, and so there can scarcely be 

 any doubt that this species has quite wrongly got the name of microtuberailatus. As a synonym of 

 it Agassiz & Desor (loc. cit.) mention Ech. pulchcllus Ag. and decoratus Ag., and the former of these 

 names should then be employed for this species. The description of Ech.pulchelliis'^) may agree rather 

 well with it, even if it cannot be said to be a very appropriate one; it might also agree with young 

 specimens of Strongyloc. lividus. Therefore I think it better to wait for a renewed examination of the 

 type specimens, before the commonly iised name of microtuberctilahis is rejected. 



Ech. angulosus is distinguished from the two other species by the two ocular plates reaching 

 to the periproct, and by the plates of the buccal membrane being fine and quite imbedded in the skin; 

 only a few are thick and carry pedicellariae. The globiferous pedicellarise have only two, more rarely 

 three teeth on either side; the tridentate ones are more strongly sinuate in the outer part where the 

 valves join (PI. XVII. Fig. 6); the larger ones have a rather strong net of meshes, the edge is thick, 

 in the lower part with very distinct transverse series of small teeth. The ophicephalous pedicellarias 

 have generally only a simple keel in the middle of the blade, without any net of meshes 

 (PI. XVII. Fig. 3). 



These three species must absolutely form a separate genus. Most recent authors use tlie name 

 of Psammechinus Ag. for them, but wrongly. In ^Catalogue raisonne> p. 64 under the fourth type 

 «Sous-genre Psammechinus Ag.» are named first the species variegatus Lamk. and scmihiberculatus 

 Val. and as no. 3 subangulosiis Lamk. There can be no doubt, then, that the two first-named may 

 claim the name of Psammechinus ., as it appears that they cannot be classed with the genus Toxo- 

 pneustcs., to which they are referred in Rev. of Ech. , but must form a separate genus (see below). 

 For the species miliaria., microtuberciclatus ^ and angulosus a new genus must then be established; I 

 propose the name of Parechinus. 



Psamtnechinus vcrruculahis Ltk. Agassiz (Rev. of Ech. p. 122) mentions this species as syno- 

 nymous with Par (ch. angulosus \ de Eoriol (245. p. 2i) objects to this and maintains that they are two 

 well distinguished species. I must not only grant that de Loriol is right in his statement, but shall 

 have to go nnich farther and assert that it cannot be referred to the same genus, nay, not even to 

 the same famil\- as Parcch. angulosus. Prof, de Loriol has kindly sent me a specimen of his 

 lEchinus vcrruculatus Ltk.^ from Maiiritiris , and so I have been al)le to compare it with the type 

 specimens of Liitken, which are foimd in the museum of Copenhagen. All the type .specimens are 

 naked tests, so that it is impossible to tell quite certainly, whether the species of de Loriol is really 

 identical with these specimens; all tlie most important characters are wanting on the naked tests — 

 nay, it is, moreover, probable that the type specimens really belong to two different species. It is, 

 however, certain, that the description given by de Loriol of the coloration of his specimens^), agrees 

 exactly witii two of the t}pe specimens, and I tliink it very likely that they are really identical. I'^ill 



•) Introduction to Valentin's Anatoniie (In pfenre Echinus, p. VI. 



-) In the specimen sent nie by de Loriol, there is no trace of coloration on the test; only the spines have the 

 colour described by de Loriol. 



