AEQUOKEA MACRODACTYLUM. 175 



rather smaller, as is the diameter of the bell. Browne records from 

 fifty-two to sixty-nine radial canals ; and from twenty-one to fifty 

 tentacles ; while Maas counted in various specimens from sixty-two 

 to one hundred and three canals and from sixteen to thirty tentacles. 

 The largest number of canals in any specimen in the present series 

 is forty-two, in an individual 22 mm. in diameter with about eighteen 

 tentacles. The smallest number observed was twenty-nine, with sixteen (?) 

 tentacles, in a specimen with no gonads, 8 mm. in diameter. In most 

 of the specimens the margins were so much damaged that it was impos- 

 sible to be confident of the complete number of tentacles ; but appar- 

 ently they were never more than half as numerous as the radial canals. 

 Between every two tentacles are a considerable number (five to eight or 

 more) of rudimentary tentacular bulbs, much as Browne has figured them 

 for the Maldive specimens (: 04, pi. 56, figs. 10-12). The tentacular bulbs 

 are of an unusual outline, and it is largely because of their form that I have 

 identified the present specimens as A. macrodactylum. When seen from 

 without they are broadly triangular, and extend in a somewhat triangular or 

 spur-like process up over the exumbrella surface of the bell (PI. 36, figs. 

 5, 6). This process shows especially well in a side view of the bulb 

 (PI. 36, fig. 8). This is essentially the conformation described by both 

 Maas and Browne, and is apparently characteristic of all specimens, though 

 varying considerably as to the exact form of the exumbral clasp. In most 

 of our specimens this is less well defined, perhaps as the result of preserva- 

 tion, than Browne found it in the Maldive specimens. The essential sim- 

 ilarity of the bulbs in A. maldivensis and A. macrodactylum has already been 

 commented upon by Maas (: 05). He has, it is true, considered these 

 two forms as belonging to different genera on account of differences in 

 the form of the mouth ; but this is a difference which, as we shall see, 

 is of very little real importance. 



Between every two tentacles there are from seven to fifteen otocysts, 

 a number agreeing with Browne's account. 



Gaslrovascidar system. — It was particularly fortunate that I was able to 

 study the collection in the fresh condition, for after preservation the lower 

 gastric wall is often so strongly contracted that if we recognized the char- 

 acter of the mouth as of generic importance we might readily class differ- 

 ent specimens in different genera. When first, taken the usual condition of 

 the mouth was that shown in PI. 36, fig. 9. I never saw any suggestion 



