68 



ECHINOIDEA. II. 



of two specimens from St. i68. A specimen from St. 244 is certainly not P. Ingnnoila ; whether it is 

 the narrow form cannot be decided with certainty, since it is very crushed, but it does not seem to 

 i)e that form — in that case the figures PI. XXXI. 7—9 would indeed be ver\- bad. Probably it is a 

 third species, related to P. pliialc. The spines are widened at the point as in the latter species. Also 

 the true P. lagimcula is represented as having the spines distincth- widened at the point (PI. XXXI. 

 Figs. 1—5); in the description they are said (p. 137) to be tapering very slightly or clubshaped . They 

 are, in fact, not at all widened or clubshaped, but several of the spines are invested towards the point 

 with a dark brown matter, the nature of which I could not decide. But in any case it is a foreign 

 matter, not part of the spine itself. The figures cited therefore give a wrong impression of this species 

 as regards the form of the spines. 



Perhaps one more species, allied to /-". Jeffrcysi and JVaiidcli. will be found to occur in the 

 northern Atlantic (warm area). Among the specimens of Poiirtalcsia W'liiidrli from the Ingolf St. 40 

 and further from St. 67 and 68 there are some small specimens (18—25'"'") ^^ a. l-'oiirfa/csia. which differ 

 from P. Wandeli in ha\ing shorter and smooth (or \ery little serrate) spines and the abactinal keel 

 more developed and produced over the periproct; the anal snout bends a little upwards. In fact 

 these specimens are rather like P. Jeffrcysi: from this species they differ, however, in having only 

 three epiproctal plates (5. a. 6 — 8 and b. 7 — 9), whereas in Jeffrcysi of a corresponding size there are 

 four epiproctal plates on each side (a. 5 — 8, b. 6 — 9); also the anal snout is flatter \xi Jeffrcysi. The 

 general shajje of the test is as in P. Wandeli, though a little narrower at the anterior end and compa- 

 ratively a little wider in the middle. The serial arrangement of the tubercles not distinct in the pos- 

 terior series of plates of the antero-lateral ambulacra. Upon the whole this form is quite intermediate 

 between P. Wandeli -Awd Jeffrcysi. uniting several of the prominent characters of these two species. It 

 further agrees rather closely with the form figured as P. iiiirajida in Pauamic Deep-Sea Ech.», 

 excepting the labrum, which is not seen from without in these specimens. — Whether this be a 

 distinct species or only a variety- of P. Wandeli (or perhaps a warm area variety of P.Jcff'reysi) I do 

 not venture to decide from the present scanty and not too well preserved material; I nnist be content 

 with calling attention to this form and leave it to those who will be so fortunate to get sufficient 

 material to decide the question. 



23. Echinosigra' (Pourtalesia) phiale ' \V\v. Thomson. 



IM. VI. Figs. 1 — 2, 7. I'l. VII, Figs, i, 7. 



Wyvilie Thomson; Depths of the Sea. p. 90. (394). Ann. Nat. Hist. 4 Ser. X. p. 305. Porcu- 

 l)ine -Echinoidea. p. 749. PI. LXX. Fig. 11. — A. Agassiz: « Challenger >-Echinoidea. p. 138. PI. XXII" 

 1—5. -XXII.a. I — 2. — D'Arcy Thompson: (392). Proc. R. Soc. Edinburgh. XXII. 1899. p. 431. — St. 

 W. Kemj); The Marine Fauna of the West Coast of Ireland. III. Echinoderm.s. .\nn. Rej). I'ish. Ireland. 

 1902—03. PI. II. App. VI. (1905). p. 206. 



■ with regard to this name, see below p. S2. 



■ In the Report on the Echinoidea of the Porcupine' W vv. Thomson writes phyatc . Both on account of jirior- 

 ity and etymology pliialc : is the correct name. 



