66 ECHINOIDEA. II. 



also mentioned iu the description (p. 345). As P. Wandeli is not mature at a smaller size than ca. 20 mm 

 length, this difference between these two species seems so essential that they conld for that reason 

 alone not be regarded as so very closely related. I must, however, be allowed to suggest, that 

 this statement of the size of the type specimen of P. miranda is a mistake. In the description in Rev. 

 of Echini as well as in the preliminary description (Bull. Mus. Comp. Zool. I. 1869. p. 272) nothing is 

 said about the size of the specimen, but in the explanation of the PI. XVIII the figure 1 is said to 

 represent the specimen magnified 3-5 in diameter . The figure being jo mm in length, this would 

 give a size of 20 ram for the type specimen. (In Three Cruises of the «Blake II. p. 101 the figures 

 from the Revision are copied in half size, and the figures are then said to represent the specimen 

 twice magnified; this would give a size of i8 mm for the type specimen). I think there can be little 

 doubt of the correctness of my suggestion as to the size of the type of P. miranda (which has, 

 unfortunately, been lost), and thus this difference between P. miranda and Wandeli is reduced to 

 nothing. (It would also be quite surprising that a specimen of so small a size as 3 - 5 mm should be 

 mature). The structure of the test of P. miranda is not worked out in the Revision of Echini , but 

 in Pauamic Deep-Sea Echini p. 140 careful figures are given thereof, from a specimen of i8 mm length, 

 collected by the Blake . This specimen, it must be conceded, agrees very closely with P. Wandeli, 

 the only differences worth mentioning being that the anal snout bends a little upwards and that the 

 labrum is large, which I have never found to be the case in P. Wandeli. Remembering, however, the 

 inconstancy of this feature in P. Jeffreysi, it is not safe to lay much stress on this single feature. I 

 thus think it very likely, indeed, that the specimen figured in the Panamic Deep-Sea Echini under 

 the name of P. miranda is identical with P. Wandeli : but on the other hand I cannot think that it 

 is really P. miranda. A comparison with the original figures in Revision of Echini PL XVIII shows 

 several important differences. The outline iu side view is very different; iu the figure in Rev. of 

 Ech. the front slopes forwards from the apical system, iu the specimen figured in Pan. Deep-Sea 

 Ech. it slopes inwards; but the anal region especially is very different, the projection over the peri- 

 proct being much larger and the anal snout turning much more upwards than in the specimen from 

 the Blake ; the snout is also much broader in the type specimen. The differences pointed out 

 here hold good also when comparing with P. Wandeli; further I may notice a very consj:>ieuous dif- 

 ference in the spines. According to the description the primary spines are long, curved, slightly fan- 

 shaped at the extremity, as also appears in the figures; no serial arrangement of the spines is indi- 

 cated on the figures or mentioned iu the text. It seems hardly possible that the serial arrangement, 

 so evident iu P. Wandeli and the specimen from the « Blake , could have escaped completely the 

 notice of the author of Revision of Echini ■, the figures looking, indeed, much too good and carefully 

 drawn for suggesting such an omission. Also the length of the spines is very different from what is 

 the case in P. Wandeli. — Further the large tentacles in the odd ambulacrum and the coloration are 

 conspicuous differences from P. Wandeli. In my opinion it can scarcely be doubted that the specimen 

 described and figured in Panamic Deep-Sea Echini as P. miranda is not that species but P. Wandeli, 

 (or a nearly related, undescribed species — comp. below), whereas P. miranda. which has still to be 

 rediscovered, belongs to a quite different type of Pourtalesise, characterized (as far as hitherto known) 

 by the broad anal snout, the large front tentacles and the comparatively short, not serially arranged 



