fore) 
SIR C. ELIOT. 
LIMACINA RETROVERSA, Fleming. 
See especially Meisenheimer on Limacina retroversa, Siidpolar Expedition (1906), IX. Band, Zool. I. Band, 
Heft II., pp. 103-105 ; Eydoux and Souleyet on Spirialis australis, Revue Zool. (1840), p. 237, and 
5 
Bonite (1852), p. 222; Pelseneer, ‘Challenger’ Report, LXV., pp. 25-27; Munthe, Pteropoder, 
pp. 8, 9 (1887). 
There are six tubes containing specimens of a whitish Limacina of small or 
moderate size, with a spire of somewhat varying height, but never so low as that of 
L. helicina or L. antarctica. The labels are :— 
Lat. 55° 44'S. Long. 95° 43’ 30” W. 5 fathoms (11 spec.). 
2. Lat. 56° 12'45"” 8S. Long. 136° 18’ 30” W. 10 fathoms (3 spec.). 
8. Lat. 57° 25'S. Long. 151° 2’ E. (Several spec.) 
4, Lat. 59° 19’8. Long. 120° 24’ 30” W. 5 ms. (6 spec.). 
5. Lat. 59° 34'S. Long. 106° 28’ 13” W. 5 fathoms (4 spec.). 
6. Lat. 61° 13’ 30" 8. Long. 173° 33’ E. (Several spec.) 
The tubes contain comparatively few specimens, and suggest that this species is 
not found in abundant shoals. 
The shells show considerable variation in form (fig. 7). No differences were 
found in the animals, though, as they were without exception retracted into 
their shells, the investigation of the foot and fins was difficult. An accessory lobe 
was, however, found on all the fins which could be extended, and after examining 
numerous specimens of ZL. retroversa from the coast of Scotland, I can confirm 
Meisenheimer’s statement (Siidpolar Exped., p. 104) that the lobe occurs in this 
northern form. The radula appears to be much the same in all specimens, and 
substantially as in L. retroversa. 
The shell varies in colour from greyish white to yellowish brown, but is always 
rather opaque, not striated, but covered with fine granulations arranged in no apparent 
order. The height of the spire varies from 1 mill. to 2 mill., the latter dimensions 
being rare, and the maximum breadth across the last whorl is 1 mill. The umbilicus 
does not vary materially in shape; it is distinct, straight, rather narrow, and 
I did not find the distinction in breadth mentioned by Prof. Pelseneer (‘ Challenger’ 
Reports LXV., pp. 26 and 27). The mouth is subquadrangular. 
The variation in the shape of the shell produces two types. Type A (fig. 74) 
is tall, with very deep sutures and six or seven whorls, which increase symmetrically 
in size, the last not being disproportionately large. In many of these shells, as 
preserved, the columella is not continued at the side of the mouth. Type B (fig. 7c) 
is smaller and lower; the sutures are not so deep; there are only four or five whorls, 
and the last whorl is disproportionately large and swollen, 
