ECHINOIDEA. II. 119 



show that tlie trideiitate pedicellariæ are richer developed. — The triphyllous pedicellariæ are as usual, 

 Uke small tridentate ones. The spicules are long, spinulose rods (PI. XIV. Fig. 27 a-b), in striking coiitrast 

 to the very small spicules of canaliferus ; they lie trans versely to the longitudinal axis of the tubefeet, 

 indistinctly arranged in two or three series. The piates of the rosette of the frontal tube-feet are well 

 developed, reaching to the point of the lobes. 



Schizaster Edwardsi Cotteau is nearly related to caiiali/crus a.\\å orbignyanits. Professor Joubin 

 has with the greatest liberality, for which I canuot thank him enough, sent me one of the type- 

 specimens for examination; I am thus able to give some additional information of characters which 

 are not mentioned in Cotteau's diagnosis of the species. The sliape of the test is upon the whole 

 like that of canaliferus; only the anterior arabulacral furrow is a little broader, its sides being almost 

 perpendicular, whereas in canaliferus they bend somewhat over the furrow. The pores are arranged in 

 a single regular series — the most jjrominent difference from canaliferus. The labrum does not reach 

 the second ainbulacral plate of the adjoiniug series; there are 5 — 6 large subanal tubefeet, the first of 

 these being on the 5th ambulacral plate. The lateral fasciole passes over the i3th ambulacral plate. 

 Only two genital pores, as pointed out by Cotteau. Of the pedicellariæ I eau give but very little 

 information, having fouud only a single small tridentate pedicellaria with simple, leafshaped valves, 

 and another small form (PI. XIV. Fig. 10) which is probably a small rostrate pedicellaria. The spi- 

 cules and rosette-plates as in canaliferus. — Though insufficiently known this species is easily disting- 

 uishéd from canaliferus by its single series of pores in the odd anterior ambulacrum and from orbigny- 

 anus (the northern form) by its spicules. But it is not possible for the present to say, if it is not per- 

 haps identical with the Caribbean form of orbignyanus, which might, from a zoogeographical point of 

 view, not be improbable. Also it has a very great likeness to Scii. lacnnosus, and it is impossible for 

 the present to give other distinguishing characters between these two species than tlieir geographical 

 distribution: one in the Indo-Pacific Ocean, the other at the Coast of Guinea; (S. lacunosus also has 

 a single series of pores in the anterior ambulacrum and quite small spicules). Before the Caribbean 

 form of S. orbignyanus has been closely examined and the pedicellariæ of S. Edivardsi have likewise 

 beeu made sufficiently known, it is impossible to judge of the specific value of these two forms and 

 their mutual relations. 



Professor Doderlein (Op. cit. p. 255) has pointed out that aniong the (recent) species referred 

 to the genus Schizaster two groups may be distinguished, differiug markedly by their globiferous 

 pedicellariæ: in one group (S. fragilis, capensis, antarcticus and ventricosus) the valves of the globi- 

 ferous pedicellariæ end in a single long, sharp tooth, in the other {S. pJiilippii, canaliferus zwA japonicus) 

 they end in 4 — 6 short teetli. Though the number of genital pores is not in accordance with this 

 grouping, as might have been expected, Professor Doderlein thinks that «nach Untersuchung auch 

 der anderen Arten von Schizaster die Aufteilung dieser Gattung in mindestens zwei Gattungen nach 

 den Merkmalen der globiferen Pedicellarien zu erwarten sei(n)». — In sRevision of Echiiii* Agassiz 

 says of Scli. ventricosus that it is intermediate between the species of the group of the genus to 

 which S.fragilis and S. Pliilippii belong and that formed by S. canaliferus and S. gibberulus>>. It follows 

 from this that also Agassiz is inclined to di vide the species into two groups, but he does not work 



