ECHINOIDEA. II. i^g 



Tlie sphæridiæ, oii the contrar\', are very early developed, viz. the first 5 of thein. Already i:i the 

 yonngest specimeiis of only O'S'"'", where remnants of tlie larval skeleton are still quite distinct within 

 the abactinal skeleton, tliey have appeared. 



In the smallest speciniens, of only 0-5""", there are already bottoni-particles in the 'intestine, 

 which shows that they begin the diet of the grown specimens as soon as their pelagic life has 

 come to end. 



Very nearly related to Ecli. cordafiiiii is Ech. aiistralc Gray, so nearly, indeed, that it niay be 

 doubted, whether they are not identical. x^gassiz, though recoguizing its close affinity to Ecli. cor- 

 datuiii, (< Revision of Echini ■ p. 580) states that specimens of this sjDecies are readily distinguished 



from the Atlantic E. cordatum Seen in profile the test rises somewhat more gradually from the 



anterior e.xtremity towards the apical system; the abactinal pole is more central, and the anal system 

 is elliptical, slightly transverse, instead of being longitudinal, as in E. cordatum. The bare abac- 

 tinal posterior ambulacral areas extend to the anibittis, remaining of the same width, instead of be- 

 coming narrow as in E. cordatum; the pores of the poriferous zones are more distant than in E. cor- 

 datum;. — In the Challenger i-Echinoidea (p. 174) these characters are stated to be quite constant in 

 the specimens examined, but Professor Agassiz adds that they «seem very slight ground for main- 

 taining the specific distinctness of the Pacific and the Atlantic representatives of the genus, and I 

 should expect that additional material will prove this species to be identical with the European species». 

 — This suggestion is probabh- quite correct. I have examined several specimens from Australia, Japan 

 and (one) from the Cape, and I find them to agree with cordatiiiii in all essential features : the labrum, 

 the number of pores included within the subanal fasciole, the shape of the anal area (as shown above 

 it is of rather variable form in cordafiii/i, so that no reliable difference is to be found herein), the form 

 and size of the petals as well as the number of their pores ( — the difference in the posterior petals 

 said to e.xist by Agassiz I am quite unable to see — ), the arrangement of the pores of the odd 

 anterior ambulacrum in double series, the position of the apical system {— I do not find it more cen- 

 tral in australc than in cordatum — ), the larger tubercles in the anterior interambulacra — in short, I 

 find them to agree completely in all essential features, so that they are, indeed, coutrary to the origi- 

 nal statement of Agassiz, e.xtremely difficult to distinguish. To be sure, I find the Ecli. australc 

 somewhat lower at the anterior end, thus rising «somewhat more gradually from the anterior extremity 

 towards the apical system«, and perhaps also the pores of the anterior ambulacrum do not become 

 arranged in double series so early as in cordatiuu} These, however, are so inconsiderable differences 

 that I doubt, whether it would be possible to distinguish with certaiuty tests of the two ^species*, if 

 they were put together and the localities of the specimens not marked. In the pedicellariæ I do not 

 find any reliable differences — but it is to be remarked that I have not found any globiferous pedi- 

 cellariæ in australc; upon the whole pedicellariæ seem to be very scarce in this form. Regarding the 

 spicules I find the large rods below the terminal disk to be generally somewhat smaller than in cor- 

 datum; on the other hånd the spicules of the frontal tubefeet are generally somewhat larger and 



I Hutton iCatalogue of the Echinodermata of New Zealand. 1872. p. 14) says of Amphidetus seatandicus (= Ech. 

 austyale) that it has four genital pores on each side; this is, of course, a mistake, caused by the ocular pores having been 

 taken to be genital pores. 



