ECHINUIDEA, 1. 177 



Hygrosoiiia ^ the diffeieiice between the hitter and the genus 7'roi/iikvs(nnii becomes rather more slight 

 than stated in the diagnoses. Then there is only any difference of importance in the form of the tri- 

 dentate pedicellarite; but this difference is so great, that I, at all e\ents for the present (until transi- 

 tional forms become known), must regard the genus Troiiiikosonia as a legitimate one. 



Kampinsoiiia astcrias (p. 60). All the three specimens from Chall. st. 272 which Agassiz has 

 determined as Phormosoma tenuef, are A', asterias. After a renewed examination I must regard it as 

 unjtTstified to establish a separate species of this genus on them. — It is the primary spines on the 

 actinal side that are flat and widened at the point (PI. XI\'. Fig. 29); below they are round, tubular, 

 and then the\' become evenly flattened towards the point. They are a little curved; a hoof is scarceK- 

 found. The spines nearest to the mouth are surrounded by a rather thick bag of skin, not widened 

 at the point. The small, accessory ambulacral plates are really wanting, only nearest to the ])eri- 

 stome a single one ma\' be found. For each ambulacral plate here are as usual three branches from 

 the radial canals, but two of them are quite thin and their ampulUe rudimentar\', and their tube feet 

 are not developed at all. 



Sperosniiia Grinialdii (p. 75). Of this species I ha\'e found ca. 20 specimens in the nniscmn of 

 Paris (;c Talisman , the Azores, Morocco, 300 — 1257 m.), determined partly as Plwriiiosoiiia iirainis, ])artl\' 

 as Asthenosoina hystrix. Our museum has further received some specimens of different sizes from the 

 Faroe Channel (59° 29' N. L. "]" 51' W. L. 580 — 689 fathoms. Michael Sars . Ad. S. Jensen), a corrobora- 

 tion of the supposition with regard to its geographical distribution expressed above. — Rather great 

 variation proves to be found in the mutrial relation of the size of the abactinal ambulacral plates; 

 accordingly there cannot be laid much stress on the deviations in this respect from the type specimen 

 of Koehler described above, and there can be no doubt that the large specimen figured on PI. I\'. 

 Fig. 3, is a real Sp. Grinialdii. 



PrioiiccJiituts sagittiger (p. 84). As far as can be seen on the t\pe specimen preserved in 

 alcohol (St. 218), no grooves are found in the test; to be able to state this fact with certainty, it will, 

 however, be necessary to examine a dried specimen. 



Ecliiiius hicidus (pjx 100, 105) has calcareous plates in the buccal membrane as the other genuine 

 jEcV/Zw^/j-species ; they are simple fenestrated plates as in Ecli. ^llrxandri. There are no spines on the 

 buccal plates (p. 161, notel. 



Stcrechinus margaritacnis {■^^. loi — 102). De Loriol has called m\- attention to the fact that the 

 figures of Ecli. margaritaccus given in Voyage de la Fregate \'enus . Zoophytes I-"!. \'I. i, do not 

 agree with Koehler's description oi St.iuitarcticiis, especially as all the ocular plates in iiiargaritaceus 

 are shut off from the periproct. Trusting to the interpretation by Agassiz of Ech. viargaritaceus as 

 the correct one, I had omitted to examine this question more closely. According to a kind informa- 

 tion from Dr. Oravier the tvpe specimen is no more found in Paris. Biit to judge b>- the figures in 

 Voyage de Venus there can scarcely be any doubt thtit Agassiz's (and my) interpretation of Ech. 

 margariiacens is incorrect; besides the ocular plates being shut off from the periproct, it seems also to 

 appear from these figures that there is a primary tubercle on all the ambulacral jolates. But then I 

 do not see how St. niagellanicus is to be distinguished from iiiargaritaccn.^, and it is an obvious sup- 

 position that they are really one species; if this be the case the name of magellanictis will onl\ be a 



The Ingolf-Expedition. l\, i. 23 



