94 
TH. MORTENSEN, 
(Schwed. Südpolar-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 pedicellariæ 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 pedicellariæ (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 pedicellaria 
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 sphæ- 
ridiæ 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 Amphipneustes 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, 8, 15, 18. PI. XII, Figs. 1, 3, 5, 7. PL XVII, Figs. 10 — 11. PI. XVIII, Figs. 1 — 2. 
PL XIX, Figs. 3—4, 8—9, 13—14, 19—20, 23—25, 27. 
Amphipneustes Koehleri Th. Mortensen. 1905. Some new species of Echinoidea. Vidensk. Medd. fra 
Naturh. Foren. Köbenhavn, p. 243. 
Among the Echini collected by the Swedish South Polar Expedition this new 
species of Amphipneustes , 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 cavernosus , 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 Amphipneustes. 
