ECHINOIDEA. n. 



119 



show that the tridentate ijedicellariic are richer developed. — The triiDhyUous pedicellarise are as usual, 

 like small trideutate ones. The spicules are long, spimilose rods (PI. XIV. Fig. 27 a-1)), in striking contrast 

 to the very small spicules of caiialifcrus ; they lie transvensely to the longitudinal a.\is of the Inbefeet, 

 indistinctly arranged in two or three .series. The plates of the ro.sette of the frontal tube-feel are well 

 developed, reaching to the point of the lobes. 



Schizaster Edzoardsi Cotteau is nearly related to canali/erus axiAorbignyanus. Professor Jonbin 

 has with the greatest liberality, for which I cannot thank h.im 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 shape of the test is upon the whole 

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

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

 a single regular series — the most prominent difference from caiialifcrus. The labrum does not reach 

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

 these being on the 5th ambulacral plate. The lateral fasciole passes over the 13th ambulacral plate. 

 Only two genital pores, as pointed out by Cotteau. Of the pedicellari^c I can give but very little 

 information, having found 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 cauali/cnis. — Though insufficiently known this species is easily disting- 

 uished from canalifcriis 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 orbigiiyaims, which might, from a zoogeographical point of 

 view, not be improbable. Also it has a very great likeness to Sch. laciiiiosiis^ and it is impossible for 

 the present to give other distinguishing characters between these two species than their 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 pedicellaria of S. Edwardsi have likewise 

 been 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 among tlie (recent) species referred 

 to the genus Sc/iizaslcr two groups may be distinguished, differing markedly by their globiferous 

 pedicellarise : in one group (S. fragilis, capensis, aiitarcticiis and vcntricosus) the valves of the globi- 

 ferous pedicellarise end in a single long, sharp tooth, in the other ( S. philippii, canali/erus and. JaponicusJ 

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

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

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

 den Merkmalen der globiferen Pedicellarien zu erwarten sei(n)». — In «Revision of Echini* Agassiz 

 says of Sch. vcntricosus that it is < intermediate between the species of the group of the genus to 

 which S.fragilis and S. Philippii belong and that formed by S. caiialifcrus and S. gibberulus . It follows 

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



