94 TH. MORTENSEN, (Schwed. Sudpolar-Exp. 



one; it is, however, to be seen that it is of the same structure as that described 

 below (p. 97) of A. Koehleri, only the valves have in addition to the two large 

 teeth in the point one or two shorter teeth. Probably this is only an abnormality 

 (also in A. Koehleri the globiferous pedicellariae have sometimes abnormally three 

 teeth in the point), so that the typical form will prove to be like that of A. Kohleri. 

 A thick skin covers the head and the upper end of the stalk as in A. Koehleri. — 

 The rostrate pedicellariae (PI. XIX Figs. 12, 17) are threevalved, rather small, with 

 the neck undeveloped (or indistinct, in any case in the samples seen by me); the 

 stalk is compact, without distinct widening above or below. The whole pedicellana 

 is invested in a rather thick skin. The blade is narrow, open, the outer part, where 

 the valves join, spoonshaped widened, with finely serrate edge; in the lower part of 

 the blade the edge is generally smooth; the basal part rather narrow. — The sphae- 

 ridiae are elongate, irregularly rugose (PI. XIX Fig. 10). 



To judge from the following species, both the type specimen of A. Lorioli 

 and the present specimen are males. It must, however, be conceded that the genital 

 pores are somewhat large for a male; and as in Abatus one species, A. Philippii, 

 has only the anterior petals transformed into marsupia, whereas the other species 

 have both anterior and posterior petals thus transformed, it may well seem possible 

 that in Ampliipneustes one species has both pairs of petals transformed into marsu- 

 pia. while the other species has none of the petals thus transformed; this species 

 would then be non-viviparous. But further material is necessary for settling this 

 question. 



Amphipneustes Koehleri MrTSN. 



PI. XI, Figs. 2—5, 7, S, 15, 18. PI. XII, Figs. 1. 3, 5, 7. PI. XVII, Figs. 10— 11. PI. XVIII, Figs. 1—2. 

 PI. XIX, Figs. 3—4, S— 9, 13—14, 19 — 20, 23—25, 27. 



Amphipnettstcs Koehleri Th. Mortensen. 1905. Some new species of Echinoidea. Vidensk. Medd. fra 

 Naturh. Foren. Kobenhavn, p. 243. 



Among the Echini collected by the Swedish South Polar Expedition this new 

 species of Ampliipneustes, of which a short preliminary description was published in 

 1905, is especially interesting. Fortunately it is rather well represented, both full- 

 grown specimens, males and females, and young ones being present. The most 

 interesting feature of this species is that the petals of the female are trans- 

 formed into marsupia, in which the eggs and young are reared, exactly in the same 

 manner as in Abatus cavemosus, with which it has also in general some resemblance; 

 it is, however, at once distinguished from the Abatus species through the lack of 

 the peripetalous fasciole and by its deep anterior abactinal ambulacrum. — I have 

 named this species in honour of my friend, Professor Koehler, the author of the 

 genus Ampliipneustes. 



