ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
341 
erroneous, has drawn up an account of his own observations. On the 
oral arms there may he seen knobs which are really little stalked cap- 
sules or pouches which contain the embryos ; these capsules are simj)ly 
evaginations of the groove of the oral arm, and lined, therefore, internally 
by endoderm, and externally by ectoderm. In the smaller capsules the 
walls are relatively thick, and contain a great deal of mesogloea, while 
the capsules themselves open by a comparatively wide opening into the 
lumen of the groove ; in the larger capsules the mesogloea is scarcely 
visible, and the openings are much narrowed. Embryos in all stages of 
development up to partly-formed planulm are to be fount!. In addition 
to those contained in the capsules, a large number are always seen lying 
free in the bottom of the groove or lodged in the foldings of its margin. 
Composite Coenosarcal Tubes of Hydroids."" — Dr. J. C. C. Loman 
discusses the composite coenosarcal tubes of Plumidaria halecioides, Cory- 
dendrium parasiticum, Antennularia antennina, some species of Tuhularia 
and Corymorplia, but especially those of Amaltlisea vardoensis n. sp. In 
Tuhularia the coenosarcal tube divides below the stomach into several 
j)eripheral branches; so is it with Corymorpha ; but the others show 
diverse conditions, and in Amaltlisea vardoensis there are offshoot canals 
from three different regions of the tube. In the last-named form, radial 
vessels proceed from the stomach to the periphery, and open between 
the tentacles like anal pores in Hydromedusse. The polype-head is 
separated from the hydranth-stalk not only by an external depression, 
but internally as well by a flat annular continuation of the supporting 
lamella, penetrated by the small opening of the coenosarcal tube, which 
at this point gives off branched anastomosing tubules upwards to the 
head and downwards to the stem. These canals are lined by flat endo- 
dermic cells, while the elements which line the above-mentioned radial 
vessels from the stomach are columnar. The latter are digestive, 
and perhaps excretory ; the former are circulatory. The constriction is 
regarded by the author as comparable to strobilization, and the species 
in question is described as a “ monodiscal strobila of a hydroj^olype.” 
It has a markedly medusoid structure, and is defined off from the stalk 
by an almost closed ring of supporting lamella and by a deep ectodermal 
groove. 
Hydroid Phase of Limnocodium Sowerbyi.f — Dr. G. H. Fowler 
made, during 1888, some observations on the hydroid phase of Limno- 
codium Sowerbyi, which was first observed by Mr. F. A. Parsons. As 
neither hydroid nor medusoid could be found during 1889, he now 
publishes his incomplete observations. The polyp has the form of a 
simple cylindrical tube about 6 mm. long, has a minute mouth and is 
always devoid of tentacles ; in spite of their absence, it catches and 
swallows small Crustaceans and free Nematodes. There is no perisarc, 
and only a loose case of vegetable detritus. The ectoderm is but little 
differentiated ; the nematocysts are, as in Hydra, of two kinds. The 
layer of mesogloea is so thin as to be practically unrecognizable. The 
cells of the upper third of the endoderm are highly vacuolated and clear, 
and pass imperceptibly into those of the lower two-thirds, which are filled 
* Tijdaclir. Neder. Dierk. Vcr., ii. (1889) pp, 2G3-84 (1 pi. and 5 figa.). 
t Quart. Jouru. Micr. 8ci., xxx. (1890) pp. 507-14 (1 p].). ° 
