Io8 ECHINOIDEA. I. 



with trois paires de pores obliques-. Now if tlie two anthors 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 

 onl)- 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 qnite wrongly got the name of niicrotubcrculatns. As a synonym of 

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

 names .should then be employed for this species. The description of Ech.pulchclhis'^) mav 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 nsed name of microtubcrculahts is rejected. 



Eck. augnloszis is distinguished from the two other .species by the two ocnlar piates reaching 

 to the periproct, and by the piates of the buccal membrane being fine and quite imbedded iu the .skin; 

 only a few are thick and carry pedicellariæ. The globiferons pedicellariæ have only two, more rarely 

 three teeth on either side; the tridentate ones are more strongly sinnate 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 pedicellariæ 

 have generally only a simple keel in the middle of the blade, withont any net of meshes 

 (PI. XVII. Fig. 3). 



These three species must absolutely form a separate genus. Most recent anthors use the name 

 of Psammechinns Ag. for them, but wrongly. In Catalogue raisonné ■ p. 64 under the fourth type 

 «Sous-genre Psammechmus Ag..> are named first the species varicgatus L,amk. and scmituberctilatus 

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

 claim the name of Psa?niiirc/i!uus^ as it appears that they cannot be classed with the genus Toxo- 

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

 For the species viiliaris^ »licrohcberculatus ^ and atignlosus a new genus must then be established; I 

 propose the name of Parechinus. 



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

 nymous with Parcch. angulosus; de Loriol (245. p. 21) 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 much farther and assert that it cannot be referred to the same genus, nay, not even to 

 the same family as Par ech. angulosus. Prof. de Loriol has kindly sent me a specimen of his 

 «Echintis vcrrtiadatus Ltk.» from Mauritius, and so I have been able to compare it with the type 

 specimens of Lutken, which are foTuid 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 the most imj^ortant 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 with two of the type specimens, and I think it very likel)' that they are really identical. F'ull 



■) Introduction to Valen tiii's Anatomie dii genre 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. 



