64 



P.R.PUGH 



Table 1 Geographical distribution of Bargmannia lata from recent Discovery collections. 



Station 



Date 



Position 



Depth (m) 



Nects 



Bracts 



8565# 1 



l-viii-74 



3°03.1'N 



23°14.3'W 



700- 800 



5 



6662#37 



21-M-68 



10°34.9'N 



19°43.7'W 



1060-1300 



24 



6662#32 



20-ii-68 



10°45.3'N 



19°51.7'W 



1210-1450 



3 



6662#30 



19-ii-68 



10°47.4'N 



19°52.7'W 



730- 795 



17 



6662#15 



16-ii-68 



10°57.0'N 



19°56.6'W 



600- 695 



27 



6662#20 



17-ii-68 



10°57.5'N 



19°49.0'W 



810-900 



8 



6662#22 



17-H-68 



10°57.6'N 



19°57.3'W 



610-680 



25 



6662#16 



16-ii-68 



10°59.4'N 



19°52.1'W 



810-890 



18 



7824#39 



10-iii-72 



11°01.1'N 



19°55.8'W 



895-1000 



5 



6662#10 



15-ii-68 



H°03.1'N 



19°59.2'W 



910-985 



4 



6662# 7 



14— ii-68 



11°04.6'N 



19°48.2'W 



715-800 



33 



6662# 8 



15-H-68 



11°08.2'N 



19°47.8'W 



910-985 



7 



7831# 1 



16— iii— 72 



13°18.4'N 



25°33.2'W 



10-1000 



12 



7803# 2 



19-ii-72 



18°06.4'N 



25° 8.1'W 



1015-1250 



13 



11261#16 



28-vi-85 



31°13.1'N 



25°18.3'W 



1000-1100 



16 



8281#29 



17-iii-73 



31°42.5'N 



63°43.6'W 



1259-1500 



26 



11794#36 



26-vi-88 



47°14.2'N 



19°31.2'W 



1200-1300 



10 



11794#83 



2-vii-88 



47°17.9'N 



19°21.4'W 



1300-1395 



7 



11794#31 



26-vi-88 



47°27.1'N 



19°18.0'W 



2500-2750 



17 



12096#2 



3-vi-90 



47°57.8'N 



16°49.6'W 



1100-1200 



16 



16 



4 



2 

 20 



4 nectophores from John Murray Expedition St. 34; 13°05.6'N, 

 46°24.7'E; 16-X-33; 0-1022 m. BMNH 1949.11.10.378; and 

 4 nectophores from Discovery St. 206; 16°36'S, 6°25. l'W; 1-v- 

 37; 1900-1500 m. BMNH 1957.5.15.111. 



Several nectophores and bracts also have been identified from 

 more recent Discovery material from the N.E. Atlantic (Table 1). 



Diagnosis. Nectophores with relatively long median thrust block; 

 with extensive ventro-lateral wings, emarginate on ventral margins. 

 Nectosac a relatively short, narrow tube without any pronounced 

 dorso-ventral undulations; squarely truncate apically. Ratio of over- 

 all length of nectophore to that of nectosac, on average, exceeds 

 1.59. Bracts large, robust, distally truncate; with semicircular dorsal 

 ridge connecting tips of baso-lateral processes and delimiting a 

 dorso-basal facet; with prominent tooth on outer lateral margin. 



Description. A photograph of the live specimen collected by 

 Alvin and taken on board the mother ship is shown in Figure 12. 

 Unfortunately, prior to photography, several nectophores had be- 

 come detached and the siphosomal stem had contracted. No 

 pigmentation is apparent in the preserved specimen, but the original 

 colour photograph indicates that the whole of the endodermal lining 

 of the stem was suffused with an orange-red colour. 



Pneumatophore. The highly distorted pneumatophore of the 

 Alvin specimen measured 2 mm in height. It is borne on a very short, 

 but probably highly contracted, stalk. 



NECTOPHORE (Figures 13-15). A total of 16 nectophores was 

 found with the Alvin specimen. The mean dimensions for the fully 

 developed nectophores of this specimen were:- length 19.44 ± 2.73 

 mm (range 14.79-23.86 mm); width 9.72 ± 1.07 mm, and the ratio 

 of total length to that of the nectosac was 1 .59 ± 0.09. Nectophores 

 of the earlier Discovery material, in the NHM, are somewhat larger 

 with an average length of 24.94 ± 6.02 mm (range 17.74-31.94 

 mm). The ratio of total length to that of the nectosac also was slightly 

 greater ratio (1.67 ± 0.10; n = 10); the same as that for Mapstone's 

 (1998) material. Similarly, the nectophores of more recent Discov- 

 ery material also are larger: length 22.89 ± 4.04 mm (range 15.8-29.6 

 mm; n = 48). These nectophores have the greatest length:nectosac- 

 length ratio of 1.73 ± 0. 1 1. However, this increase in ratio probably 



Fig. 12 Bargmannia lata. Photograph (reproduced by kind permission of 

 Larry Madin, WHOI) of live specimen collected during Alvin Dive 966. 

 Nectosomal length c. 5 cm. 



