ECHINOIDEA. I. 



145 



Echinoidea p- 115) is incorrect (see below). Agassiz (< Challengers-Echiuoidea p. 213) states that it is 

 also fouiid in the Mediterranean, off Tristan d'Acunha and Papua > (more exactly: the Admiralty 

 Islands), and these statements are adopted bj- Hov le and Bell. I cannot dispute the occurrence in 

 the Mediterranean, as I have not seen the specimens upon which the statement rests; on the other 

 hånd I must maintain that the other statements are incorrect, as I have examined the specimens from 

 <Challenger; that Agassiz has determined as Ecli. clcgaiis (Chall. Ech. p. 115). The specimen from 

 sL 46 (south of Nova Scotia, 1350 fathoms) is a large, fine specimen of Ech. Alcxaiidri. Those from 

 Tristan d'Acunha are likewise a large, fine form, very similar to Ech. A/rxai/dri (the more long-spined 

 forms). Its narrow tridentate pedicellariæ , however, show that it cannot be tliis species; presumably 

 it is a new species, which seems to be most closely allied to Ech. /ucidu.<; Doderl. The specimens from 

 st. 219 (the Admiralty Islands), on the other hånd, are something widely different from Ech. rlrgmis: 

 There is an unpaired lateral tooth on the globiferous pedicellariæ, and according to my observations 

 by the short examination during my stay at British Museum I feel inclined to think that it is nearly 

 related to Arbacina forbesiaiia; at all e\-ents it is a sure faet that it has nothing to do with Ech. 

 clt'gaiis, and upon the whole does not belong to the family Echhiidæ. 



Thus a great uncertainty is seen to have been prevailing with regard to the interpretation of 

 tilis species. The description of Ech. clcgans given by Agassiz in Rev. of Ech..>, does not agree 

 with this species, but with EcJi. itnrvrgiciis, and the figure given (PI. VII. a. Fig. 4) seems also to be 

 Ech. iiorvcgictis; it is not, however, to be seen with certainty, as the specimen has been less well 

 preserved. — In conformit>- to this wrong interpretation of Ech. elegans Agassiz seems to have esta- 

 blished a new species, EcJi. Wallisi., for the real EcJt. clcgaus. As mentioned above (p. loo) I have 

 received a specimen from U. S. National Museum, determined as Eclt. Wallisi^ which is no doubt a 

 large specimen of Ech. chgaiis, only a little more short-spined than is usually the case. But I think 

 it must be regarded as a little doubtful, whether it is really Ech. Wallisi. It does not agree ver\' well 

 with the description of this species, especially must be pointed out that its pores are trigeminate as 

 usual in Echimis. But, according to Agassiz Ecli. Wallisi is distinguished by < the arrangement of 

 the pairs of pores in sets of two - (• Blake -Echini p. 39). — It is impossible for me to decide how the 

 faet really is, but to judge by this specimen it is a sure faet that Ech. elegans is found off North 

 America, and that Eclt. Wallisi is either synonymous with it — but then its pores are trigeminate 

 and not in - sets of two > — or that it is a separate species with the pores in sets of two;, but then it 

 is no Echimis. At all events it is to be regretted that Agassiz has given a so deficient description 

 of a new species, and, moreover, has not given any figure of it at all. 



Judging from the material of Ech. rlcgavs we have from the Ingolf-Expedition, it is a very 

 varying form. If we compare the test of a subconical and a higher form, we might be led to sup- 

 pose them to be two separate species. But transitional forms are found, and especially no difference 

 seems to be found in the pedicellariæ. For the present I must regard tlieni all as one species, but 

 the possibility is not excluded that by means of a larger material we niay be able to distinguish dif- 

 ferent forms. It is, however, I think, more likely that it will show a richness in forms similar to that 

 of Echimis Alexaiidri ., in which case the Challenger-specimens from Tristan d'Acunha will perhaps 



nevertheless have to be referred to EcJi. clcgans. 



19 



The Ingolf-Expedition. IV. i. 



