182 
have two pairs of lateral cusps; although in the shorter, more 
rounded bracts, one or both of the more distal pair could be difficult 
to discern. Both types had a patch of small epidermal cells on the 
dorsal surface, but the positioning differed (Fig. 20). Often these 
patches had been abraded away. Proximally the bracteal canal 
originated on the dorsal surface of the bract. It passed down the 
middle of the ventral side bract and, for the most part, lay in close 
contact with its surface. A short distance from its distal end it 
narrowed and penetrated through the mesogloea to terminate be- 
neath a hemispherical clump of epidermal cells sunk into the 
mesogloea. Some of these cells, as with the patches on the dorsal 
surface of the bract, probably produced bioluminescence; others 
were nematocysts measuring 80 x 20 um. 
GASTROZOOID. (Fig. 21A). Up to 7.5 mm long, with no obvious 
pedicle. The basigaster, to which the tentacle was attached, was 
minute. The gastrodermal lining of stomach region bore a complex 
pattern of villi; while the proboscis was broad and elongate, with a 
distinctive arrangement of eight stripes. 
TENTILLUM. (Fig. 21B). The tentillum was very distinctive, witha 
thickened pedicle, occupying about half its length, through which 
the broad gastrovascular canal passed. The distal half of the tentillum 
consisted of an extensive cnidoband and a process, containing a 
canal, that bent away, occasionally at a right-angle, from the base of 
the cnidoband and was terminated by a small spherical swelling. The 
cnidoband appeared to have two rows of large nematocysts on either 
side, measuring 120 x 20 um, that, judging by those that had been 
discharged, probably were homotrichous anisorhizas. The remain- 
der of the cnidoband bore numerous smaller nematocysts of two 
sizes; the more cylindrical ones measuring c. 21 x 12 um, and the 
more ovoid ones c. 26 x 15 um. These were the only nematocysts to 
be found on the distal tip of the cnidoband. 
PALPON. (Fig. 21C). Up to 4 mm long, with a palpacle, without 
nematocysts, at its base. Proboscis region long and narrow with 
broad gastrovascular canal. 
DISTRIBUTION. Known only from a single specimen collected in 
the region of The Bahamas. 
REMARKS. Although Parerenna emilyae possesses the general 
erennid characters, there are certain differences from those of the 
genus Erenna that warrant its placement in a separate genus. Prima- 
rily, the nectophores are not flattened dorso-ventrally and only the 
apico-lateral ridges are distinct. The weak infra-lateral ridges do not 
demarcate the lower margins of the lateral facets, and the weak 
vertical lateral ridges have an oblique course. Further, the lateral 
radial canals on the nectosac are slightly curved. In addition the 
basigaster of the gastrozooid is minute, especially in comparison 
with the greatly expanded basigasters of the Erenna species. 
ETYMOLOGY. The species is named for my daughter Emily. 
KEY FOR THE IDENTIFICATION OF 
ERENNID NECTOPHORES 
I Nectophores dorso-ventrally flattened with distinct, short vertical lat- 
eral ridges, and apico- and infra-lateral ridges joining apically. Genus 
PETEVNG . os csussssonsiovonsievnscevdeesdhettadanacsbessanurte cate tee rere Pitiasascme bats <eceeenast 2, 
Nectophores not dorso-ventrally flattened; indistinct vertical lateral 
ridges; indistinct infra-lateral ridges not joining apico-laterals apically. 
Genus: Pave renin sic. icasvgeswnctzoscuacueagMevseeieteinprenssennseocietnnanaest P. emilyae 
P.R. PUGH 
2 Two digitate processes on ventral side of thrust blOCK «00... cess 
Erenna richardi 
No digitate processes on ventral side of thrust block... 3 
3 Apico-lateral ridges divide close to ostium; thrust block with V-shaped 
median indentation; no ‘horn’ canals ..........c0ceeee Erenna laciniata 
Apico-lateral ridges do not divide close to ostium; thrust block with- 
out median indentation; ‘horn’ canals usually present ..............000 
ssesudsacvnannslenenskennas ead enprcte-tverenesuadaiic#sencecseteenaaees a aetna Erenna cornuta 
ACKNOWLEDGEMENTS | am extremely grateful to Drs Richard Harbison 
(WHOI) and Edie Widder (HBOJ) for inviting me to participate in several 
cruises involving the use of the Johnson-Sea-Link submersibles, and for 
allowing me to use the siphonophore material collected. The reviewers’ 
comments were greatly appreciated. I am also grateful to Mike Conquer 
(SOC) for teaching me how to scan the figures. 
REFERENCES 
Alvarino, A. 1969. Zoogeografia del Mar de Cortés: Quetognatos, Sifondforos y 
Medusas. Anales del Instituto de Biologia, Universidad Nacional Autonoma de 
México. Serie Ciencias del Mar y Limnologia, 40(1), 11-54. 
1980. El plancton del Atlantico suroeste. Dindmica y ecologia. Boletim do 
Instituto Oceanografica, Sao Paulo 29, 15-26. 
1981. Siphonophorae. Jn ‘Atlas del Zooplancton del Atlantico Sudoccidental’ (D. 
Boltovskoy, ed.), pp 383-441. Instituto Nacional de Investigacién y Desarrollo 
Pesquero (INIDEP), Argentina. 
Bedot, M. 1904. Siphonophores provenant des campagnes du yacht Princesse-Alice 
(1892-1902). Résultats des Campagnes Scientifiques accomplies par le Prince 
Albert I. Monaco 27, 1-27. 4 pls. 
Bigelow, H.B. 1911. The Siphonophorae. Memoirs of the Museum of Comparative 
Zoology, at Harvard College 38, 173-402. 
Daniel, R. 1985. Coelenterata: Hydrozoa Siphonophora. The fauna of India and 
adjacent countries, Zoological Survey of India, 440 pp. 
Leloup, E. 1936. Siphonophores calycophorides (suite) et physophorides provenant 
des campagnes du Prince Albert ler de Monaco. Résultats des Campagnes 
Scientifiques accomplies par le Prince Albert I. Monaco 93, 1-36. 
1980. A propos du siphonophore Erenna richardi Bedot, 1904. Bulletin de 
l'Institut Royal des Sciences Naturelles de Belgique 52 (11), 1-4. 
Lens, A.D. & van Riemsdijk, T. 1908. The Siphonophora of the Siboga Expedition. 
Siboga-Expeditie (Siboga Expedition) 9, 1-130. 
Margulis, R.Ya. 1969. Distribution of some siphonophore species of the suborder 
Physophorae in the Atlantic Ocean. Vestnik Moskovskogo Universiteta 24, 17-38. 
(In Russian). 
1977. New data concerning the colony structure in Erenna richardi (Physophorae, 
Agalmidae). Zoologicheskii Zhurnal 56, 148-151. (In Russian). 
1990. Does the species Erenna bedoti (Siphonophora, Physonectae) exist? 
Zoologicheskii Zhurnal 69, 138-142 (in Russian). Translation in Hydrobiological 
Journal 27, 30-34, 1991. 
Moser, F. 1925. Die Siphonophoren der Deutschen Siidpolar-Expedition, 1901-03. 
Deutsche Siidpolar-Expedition 17 (zool 9), 1-541. 
Musayeva, E.I. 1976. Distribution of siphonophores in the eastern part of the Indian 
Ocean. Trudy Instituta Okeanologii 105, 171-197. 
Pugh, P. R. 1975. The distribution of siphonophores in a transect across the North 
Atlantic Ocean at 32°N. Journal of Experimental Marine Biology and Ecology 20, 
77-97. 
1989. Gelatinous Zooplankton — the forgotten fauna. Progress in Underwater 
Science 14, 67-78. 
1998. A re-description of Frillagalma vityazi Daniel 1966 (Siphonophorae, 
Agalmatidae). Scientia Marina 62, 233-245. 
—— 1999. A review of the genus Bargmannia Totton, 1954 (Siphonophorae, 
Physonecta, Pyrostephidae). Bulletin of the Natural History Museum, London (Zool- 
ogy Series) 65, 51-72. 
Totton, A.K. 1965. A Synopsis of the Siphonophora. London: British Museum (Natural 
History). 







