Fewkes.] 320 {November 5, 
ridges, less developed to be sure, are found in all the Diphyidae. 
Perhaps no where is this development carried so far as in the two 
irregularly circular lappets under the opening of the bell in Epibulia 
(Galeolaria), which structures play such an important part in direct- 
ing the animal as it darts back and forth through the water. 
The two-paged paper of McDonald} on the nervous system in 
Diphyes, Leuckart in his ‘‘ Bericht, ” rightly criticizes as follows : 
‘Was McDonald bei Diphyes als Nerven-system beschreibt, reducirt 
sich auf die an die Schwimmglocken tretenden und darauf sich ver- 
theilenden Gefisse.” He does not add upon what ground he bases 
such a conclusion. In Abyla the resemblance of these so-called 
tubes to a nervous system is great, but we know so little of their 
nature, and indeed of their course, even in the distal swimming bell 
of such a common Calycophore as Diphyes Sicboldii, that at present any 
generalization is premature. It seems to me that these structures — 
are homologous to the chymiferous tubes on account of their position, 
and origin. I cannot understand, however, how what McDonald gives 
‘‘ affords presumptive evidence of the existence of a similar system in 
other forms of Oceanic Hydrozoa, ” as the title to his paper reads. 
In Physophora, Halistemma, Agalma and Stephanomia (Forskalia), 
we know that similarly placed structures in the nectocalyces are 
chymiferous vessels similar to those found in the hydroid Medusa. 
In Epibulia (Galeolaria), the Calycophore where these structures in 
the distal nectocalyx have often been described ? and figured, they are 
without doubt true tubes as in the Physophoridae already mentioned. 
Such facts render it probable that these are also chymiferous tubes in 
Abyla. 
Leuckart says, * “ Die Firste, die den Langskanal bildet, ist ohne 
gefass.” The “langskanal,’’ if I am not wrong, is the same as the 
cavity or canal on the under side of the larger nectocalyx, as it gene- 
rally swims, one side of which is formed by what I have called a plate. 
Into this cavity the stem can be drawn. My specimens, which are 
from the Mediterranean, show the rudimentary tube, which I figure. 
i Ann.and Mag. Nat. Hist., 114-116. : 
2 Gegenbaur. Beitrage zur naiheren Kenntniss der Schwimmpolypen, 1854, p. 
35, Taf. xvi, fig. 8. Leuckart. Siphonophoren von Nizza, p. 33-34, Tab. X1, fig. 14. 
See also Zool. Untersuch. Vogt, Sur les Siphonophores de la Mer de Nice. Delle 
Chiaje. Descriz., etc., V, p. 185. 
3 Zoologische Untersuchungen, p. 57. 
