K. FRAUSSEN & J. ROSADO 
The Cantharus group on Almirante Leite bank 
Pallia sp. 
Fig. 12 
Material. Mozambique Channel, Almirante Leite 
Bank, MAINBAZA stn. DW3168, 26°12’S, 35°03’E, 
87-90 m, 1 dd. 
Remarks. The single dead collected specimen has a 
slightly damaged columellar part of the siphonal canal 
and is characterized by the protoconch which consist 
of a single whorl with a rather broad, but slightly 
flattened tip. 
The shell is similar to Pollia imprimelata sp. nov. 
in spiral sculpture, but differs by the protoconch 
which consist of a single whorl (instead of 2 whorls) 
with a flattened tip, the more convex whorls resulting 
in a more convex adapical part of the aperture and a 
shape typical of the genus, the adapical part of the 
axial ribs which is weaker and the smaller adult size. 
Pollia subcoslata (Krauss, 1848) (type locality “In 
litore natalensi”: South Africa, Natal, littoral), a 
species which also lives along the coast of 
Madagascar and Mozambique in shallow to fairly 
deep water, is easily distinguishable by the bigger 
spiral cords and by the body whorl with weak or 
absent axial sculpture. P. subcoslata also has a thicker 
shell, a darker colour and a thick periostracum, but 
these three features may vary in the genus, according 
to bathymétrie occurrence. 
Micrologus gen. nov. 
Type species. Micrologus mochatinctus sp. nov. (type 
locality: Mozambique Channel, Almirante Leite Bank, 
MAINBAZA stn. DW3169, 26 0 U’S, 35 o 01’E, 450 m 
deep). 
Diagnosis. Shell rather small. Shape semi-oval; spire 
moderately high, fusiform; base slightly stretched. 
Protoconch paucispiral, consisting of about 1 smooth 
whorl; surface rather rough, covered with minute 
shallow holes. Transition to teleoconch indistinct, 
marked by the start of the sculpture of the teleoconch. 
Spiral sculpture fine, consisting of thin primary spiral 
cords (4 on first whorl, 5 on other spire whorls, 11 on 
body whorl). Spiral interspaces broad on periphery, 
with 1 (on upper spire whorls) to 3 (on fourth whorl to 
body whorl) fine secondary spiral threads of equal 
strength, occasionally 4. 
Axial sculpture consisting of broad ribs with broad 
interspaces, running from suture to suture on spire 
whorls, from suture to just below midwhorl on body 
whorl. 
Aperture large, ovate, adapically slightly pinched with 
a single columellar knob and a labral knob bordering 
the anal notch. Columella strongly concave, smooth 
and glossy, with an adapical columellar knob 
(bordering the anal notch) and a strong abapical 
columellar knob on transition to siphonal canal. Callus 
thin, smooth, glossy, broad; abapical part more 
developed, forming a broad layer well adhèrent to 
columella. Outer lip rounded, lip thick, edge sharp, 
with broad, but low internai knobs, not situated 
according to primary spiral cords on outer side; 
adapical knob slightly bigger, occasionally split; 
abapical knob slightly bigger, on transition to siphonal 
canal. This abapical knob not situated in front of 
abapical columellar knob but strongly diagonally 
orientated to each other. Labral varix low but broad, 
slightly prosocline. Siphonal canal short, broad, open. 
Comparison. The diagnosis is based on the single 
known species, described below. Therefore we do not 
know the magnitude of variation within the genus. 
Based on known variability in other généra of the 
Cantharus group we may assume with some certainty 
that the way the spiral cords are arranged is a solid 
diagnostic feature, as well as the convex shape of the 
teleoconch whorls and the narrow siphonal area 
without constricted base. Contrary to the strength of 
the primary spiral cords, the width/length index and 
the size are features variable in most other related 
généra. 
Hesperisternia Gardner, 1944 (type species: 
Hersperisternia waltonia Gardner, 1944: 445-447, 
from the Miocene of Florida), has a similar sculpture 
consisting of fine spiral cords and a columellar fold on 
the transition to the siphonal canal. The strongly 
sculptured species of that genus look much different at 
first glance, but the more subtly sculptured species 
like H. multangula grandanus (Abbott, 1986) and H. 
shaskyi (Berry, 1959) hâve a similar spiral sculpture 
consisting of a few primary spiral cords with many 
fine secondary spiral threads of equal strength in the 
interspaces. Hesperisternia species differ from the 
new genus by the presence of 3 dominant spiral cords 
on the periphery (while in Micrologus gen. nov. ail 
primary spiral cords, also on the base, are of a rather 
equal strength); the secondary spiral cords of unequal 
strength, the decreasing number of axial ribs towards 
the body whorl; the presence of well developed 
sculpture in the aperture and the shorter, slightly 
twisted siphonal canal with a slightly more 
pronounced umbilical fissure and a slightly more 
constricted area between base and siphonal canal. 
Hesperisternia waltonia Gardner, 1944 (type 
locality: “No. 3742, Shell Bluff, Shoal River, Walton 
County, Florida”), the type species of the genus, is 
described with 3 protoconch whorls while Recent 
species of that genus hâve 1 to 1 3 A protoconch whorls. 
Hesperisternia shaskyi (Berry, 1959) (type 
locality: south olï Guaymas, Sonora), which is in fact 
not a typical species of its genus, is ornamented with a 
spiral sculpture most similar to Micrologus gen. nov. 
(evenly spaced primary spiral cords, secondary spiral 
cords of more or less equal strength) and a weakly 
sculptured aperture, but differs (apart from the broad 
shape and distinct range) by the more constricted 
shape of the base, the shorter siphonal canal and by 
the broad spiral cords on the siphonal canal. 
