BARGMANNIA REVISION 



57 



also are present, which are largely colourless and transparent, with 

 only small patches of endodermal cells in the stomach region. 



No mature tentilla remained with the specimens. The immature 

 tentilla (Figure 5A) conformed to the basic Bargmannia design, with 

 the cnidoband ranging from being straight to curved or slightly 

 twisted. There was a maximum of only six large nematocysts, 

 probably stenoteles, that measure c. 1 20 by 80um, irregularly arranged 

 on the proximal region of the cnidoband. About half the circumference 

 of the cnidoband is covered with rows of twoothertypesof nematocysts; 

 one is ovoid, measuring c. 16 x 11 urn; and the other is spherical, 

 measuring c. 8.5um in diameter. Similar nematocysts are also present 

 on the terminal filament. It has not been confirmed that these 

 nematocysts are the acrophores and desmonemes that are typically 

 found on the terminal filaments of many physonect species. It is, 

 however, unusual to find such small nematocysts on the cnidoband. 

 The terminal filament obviously can extend to a considerable extent, 

 but in the preserved specimens it is generally tightly coiled. 



SiPHOSOMAL TENTACLES AND BUDS (Figure 5B). Midway between 

 each gastrozooid a peculiar tentacular structure is attached directly 

 to the siphosomal stem. In the preserved specimens they are usually 

 tightly coiled, but some relaxed ones can reach lengths of 8 mm. 

 Along one side there is a biserial arrangement of spherical 

 nematocysts, c. 1 3 urn in diameter, similar to those on the cnidoband 

 of the tentacle. The gastrovascular canal is lined by an irregular 

 honeycomb of large endodermal cells. 



In addition to the siphosomal tentacle, small bud-like structures 

 were noted protruding from the stem. Because the siphosome in both 



specimens was tightly coiled it was not possible to assess the precise 

 disposition of these buds. However, their arrangement may be 

 similar to that which will be described for the following species. 



GONOPHORE (Figure 5C). Both the Alvin specimens are male and 

 bear numerous gonodendra at various stages of development. The 

 gonophores measure up to 4 mm in length, including the pedicel. 

 They appear to bud one from another to form a small gonodendron. 

 If the gonophores becomes detached, their thin-walled pedicels 

 remain, giving the false impression of the presence of gonopalpons. 

 Again, since the stem is highly contracted, it is difficult to ascertain 

 their exact disposition. 



Remarks concerning the identification of Bargmannia 

 ELONCATA. Complete and well-preserved specimens offi. elongata 

 easily can be distinguished from the other Bargmannia spp., particu- 

 larly as the form of the bracts is very distinctive. For the nectophores, 

 the arrangement of the apico-lateral ridges, with their distinct right- 

 angled bend and the presence of the short extra ridges branching 

 from them, also are characteristic features. However, in the case of 

 net collected material, which is usually damaged or distorted, the 

 nectophores of this species may be difficult to distinguish from those 

 of the following species, as is discussed further after its description. 



Bargmannia amoena sp. nov. 



Holotype. BMNH 1998.2164, preserved in Steedman's solution, 

 collected during JSL II Dive 1458 off Dry Tortugas, Florida; 

 24°00.6'N 82°17.4'VV; 3.ix.l987; 841m. 



Fig. 6 Bargmannia amoena sp. nov.. Photographs (taken by Ron Gilmer) of live specimen collected during JSL II Dives 968 (A) and 1687 (B). 

 Nectosomal lengths: A. c. 5 cm, B. c. 7 cm. 



