KCHINOIDEA. II. g^ 



emphasized by Aoassiz. It is mainly the large frontal tiibc-fcet which are taken as a proof of this 

 affinity — «the striking rescnihlaiice of tlie \oung Brissopsis with its gigantic snckers in the odd 

 anterior ambulacrum (I'lev. of Kch. PL XIX. i— 2) to the full-grown A'eropc, plainly shows the Hrissoid 

 affinities of the genns» («Chall. -Kch. p. 190); but also the shape of the test i.s, if I understand it rightly, 

 taken as a proof of this affinity ( Chall. >-E;ch. p. u;6). Quite a])art from the fact that it .seems rather 

 exaggerated to term the frontal tube-feet of the young Brissopsis < gigantic , this isolated feature, the 

 large frontal tube-feet, does not appear to me a sufficient proof of near relation betsveen these other- 

 wise very different tj-pes; the subanal fascicle so characteristic of /irissopsis seems especially a proof 

 again.'^t the suggested affinity with Aeropsis and Acrstr. Also the structure of the globiferons pedi- 

 cellariae is a proof against more close affinity of these forms, far more important than a possible 

 resemblance in the shape of the test of Accsfr when seen in end view. 



If the view expressed above (p. 84 — 85) of the ])rimary classificatory imixirtance of the structure 

 of the sternum be correct — of which I for my part am fully convinced — it natnralh- follows that the 

 affinities of Aeropsis and Accstc to Pourtalcsia and other Ananch)-tid genera, likewise repeatedly emjjh- 

 asized by Professor Agassiz, are not real; they are merel\- superficial analogies. Aeropsis and Accste 

 are rather primitive amphisternous forms, which cannot be more closely related to the higher meri- 

 dosternous genera, and neither can they be taken as showing the passage of the Ponrlulesia-^xowi^ 

 to the Brissina among the Spatangoids ( Chall. -Ech. p. 190). 



26. Heniiaster expergitus Loven. 



PI. 11. Figs. I, 4, iS, 20. PI. IV. Figs. 6—8, 10—12. PI. XV. Figs. 9, 16—18, 24, 26, 30—31, 35, 38, 44—45, 47—48, 50. 



vS\nou}'ms: Ihiniastcr zona f lis A. Ag. 



— gihbosics A. Ag. (? — see below, p. 102 — 5). 



— Mciitzi A. Ag. 



Literature: Loven: Etudes sur les Echinoidee.s. p. 13. PI. V. 46— 47. XI. 93— 94. XIII. 114— 20. 

 XXVI. — On Pourtalesia. p. 53. PI. X. 92. XMII. 222. — Bernard (78). — Th. Mortensen: Some new 

 species of Echinoidea. p. 243. 



The specimens of ITciniastrr dredged by the .Ingolf-, « Michael Sars and Thor must un- 

 doubtedly be referred to the species described by Loven, H. rxpergitns. Professor Theel most kindly 

 sent me the type specimens of E o v e n so that I have been able to make a direct comparison, and 

 the identity is thus established beyond doubt. The species was hitherto recorded, since Loven, only 

 from the «Talisman» by Bernard, and it is thus a fact of no small interest that it now proves to 

 occur also in the northern Atlantic, and e\-identh- not very rarely. The sisecimens before me are of 

 different sizes, from 5""" to 37""" in length; I have further taken a quite young specimen of only 3""" 

 length off Frederikssted, vSt. Cruz, ca. 500 fathoms, which evidently belongs to the same species. (Loven 

 had only a pair of young specimens of 10—14'"'" length). We are thus able to follow the changes 

 which appear with age. 



The shape of the test is seen from the figures representing the naked test and the test with 

 the spines (PI. II. Fig.s. i, 4, 18, 20. PI. IV. Ing.s. 6 — 8,10—12). The outline is oval, a little broader in the 

 anterior half. The abactinal side is almost flat, sloping rather strongly from behind towards the front, 



The Ingolf-Expedition. IV'. j. \x 



