
Fig. 13 Erenna laciniata. Photograph of part of siphosome showing male 
gonophores. 
short, brown-coloured stripes. No nematocysts were found on the 
palpacle. 
GONODENDRA. (Figs 11D, 13). The JSL 1688 specimen was fe- 
male and the gonodendra were arranged in a very similar fashion to 
that described in Erenna richardi. The JSL 1454 specimen was 
male, with the individual gonophores apparently scattered randomly 
down the stem (Fig. 13). Each was a relatively large medusoid, 
whose manubrium progressively filled with spermatozoa until it 
occupied almost the entire subumbrella cavity (Fig. 11D) and had a 
milky-white colour. 
DISTRIBUTION. The JSL II Dive 1454 specimen came from the 
region of the Dry Tortugas between Florida and Cuba, while the 
Dive 1688 specimen came from the region of The Bahamas. In 
addition, some damaged nectophores that can be referred to this 
species have been found in the Discovery collections from indi- 
vidual hauls on the equator at 22°W (805-900 m) and at 3°N 23°W 
(O—1000m). 
BEHAVIOUR. In life the terminal process of the tentillum was 
reddish-brown in colour. It was kept rigid and was vibrated rapidly 
presumably, as was suggested for Erenna richardi, as a form of 
aggressive mimicry. 
ETYMOLOGY. The specific name, being Latin for a ‘flap’, refers to 
the lateral flap-like process on the bracts. 
Erenna cornuta sp.nov. 
HoLotyPe. The JSLII Dive 1451 specimen is designated holotype, 
and has been donated to the Natural History Museum, London 
where it is registered as BMNH 2000.1818. 
MATERIAL EXAMINED. The description is based on a single speci- 
men collected during JSL II Dive 1451 at a depth of 896 m. (29 viii 
1987; 24°30.6'N 83°45.6'W). In addition, a few specimens that 
apparently can be referred to this species have been found in recent 
Discovery collections, but always in a poor state of preservation. 
DIAGNOSIS. Nectophores relatively less dorso-ventrally flattened, 
with only the basic ridge pattern; with apico-laterals not dividing 
close to ostium. Thrust block small, with no median indentation or 
conical protuberances. Lateral radial canals typically have ‘horn’ 
canals branching off at apico-lateral margins of nectosac. Bracts 
P.R. PUGH 

Fig. 14 Erenna cornuta. A. upper and B. lower views of nectophore with 
‘horn’ canals; C. upper view of nectophore without ‘horn’ canals. D. 
upper view of young nectophore. Scale 2 mm. 
with weak transverse ridge. Tentilla of two characteristic types; one 
with a long pedicle and no terminal process, with nematocysts 
grouped into four circular processes; the other with shorter pedicle 
and a small vesicular terminal process; with nematocysts, on the 
long cnidoband, more or less separated into c. 17 bundles. 
DESCRIPTION 
PNEUMATOPHORE. Measured c. 1.5 x 1 mm, but its base has been 
ruptured by gas expansion. No obvious pigmentation. 
NECTOPHORE. (Fig. 14). Thirteen large nectophores, plus two 
developing ones and some nectophoral buds, were found with the 
specimen. They measured up to 16 mm in length, 14 mm in width 
and 4 mm in depth. The ridge pattern comprised pairs of apico-, 
infra- and vertical laterals. The apico- and infra-laterals unite close 
to the apices of the axial wings. The infra-laterals extended basally 
to end below the ostium. The apico-laterals, on mature nectophores, 
were only prominent in the upper half of the nectophore and, unlike 
the two species described above, basal to the vertical lateral ridges, 
they curved in toward the mid line (Fig. 14A, C). They could be 
traced, usually only after staining, down further toward the ostium, 
but did not divide. On the youngest nectophore the apico-laterals 
rapidly approached and then overlapped each other, ending just 
above ostial level (Fig. 14D). 
No obvious mouth plate and the ostium opened basally. On each 
side of the ostium there were prominent lateral processes with 
obvious strips of epidermal cells; with a smaller triangular patch of 
cells found dorsally. In addition, there was a pair of small patches of 
cells on either side of the nectophore; above the mid-height of and 
basal to the vertical lateral ridges. All these patches were believed to 
be sites of bioluminescence. 
T-shaped nectosac with a distinct apical muscle-free area, par- 
ticularly on its ventral side. Pallial canal short, extending from the 
base of the thrust block over on to the ventral surface of the 
nectophore, where it gave rise to the pedicular canal. On the 
nectosac the latter immediately divided to form the four straight 
radial canals. No pigmentation was noted in any canals. The lateral 
