ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 635 



sac is regarded as being the homologuc of the hood of other Diseo- 

 phora. In development an unequal segmentation is to bo observed, 

 and as this segmentation takes place in the water we cannot regard 

 the subumbral pouches as being receptacles for the developing young. 

 During the ephyra stages the cavity of the stomach becomes differ- 

 entiated into an upper and a lower story by the " growth of a con- 

 tinuation of the lower floor of the bell into a partition in this 

 structure." 



Steplianomia atlantica is a new species of that genus of the Sipho- 

 nophora which is distinguished by the multiscrial arrangement of the 

 swimming bells ; the nectocalyces are much more numerous than in 

 Agalma or Halistemma, and allow of more varied motion on the part of 

 the animal, and a rotation of the stem is sometimes combined with a 

 direct forward motion. Agalma papillosum, Agalmopsis fragile, ffliizo- 

 physa gracilis, and Athoryhia formosa are new species; in the last 

 we find two different kinds of tentacular knobs hanging from one 

 tentacle. 



Ealitiara is the name applied to a new genus of Hydroida ; this 

 Tubularian medusa has a tall bell with a small apical projection, four 

 chymiferous tubes without lateral glands, four long tentacles with 

 three small ones between each, and no otocysts. H. formosa n. sp. 

 Another new genus is Halicalyx, H. tenuis; Aglaura vitrea n. sp., 

 allied to and perhaps identical with the common A. hemistoma. 



Three new genera of Hydroids resulted from the exjilorations of 

 the United States Fishery Commission : Calycopsis (G. typa) is related 

 to Turris, but is distinguished by the presence of sixteen instead of 

 four radial tubes, a point in which it differs from all known Antho- 

 medusa3 ; Chromatonema (G. rubrum) is a form the alliances of which 

 are still somewhat obscure. Halicreas (S minimum) has " eight 

 prominent rounded projections covered with tubercles on the bell 

 margin at the extremity of eight radially arranged ribs passing from 

 centre to circumference of the bell. No proboscis. No tentacles." 

 Apparently allied to the Narcomedusfe, it differs from all of them in 

 the presence of the eight radial stripes in the bell, and the eight 

 marginal tubercles. There is a velum which indicates that it is a 

 true Hydroid medusa. 



The author discusses the development of the chymiferous tubes in 

 Mnemiopsis leidyi and points out the radical differences between it and 

 Bolina, the history of which has been related by A. Agassiz. 



Sense of Smell in Actiniae.*— Mr. W. H. Pollock and Dr. G. J. 

 Romanes have found that the common sea-anemones are conscious of 

 the presence of any kind of food (pieces of cockle, mussel, &c.) placed 

 near them. If the food was held within a span's breadth of an indi- 

 vidual anemone the creature opened ; if it was held in the centre of 

 a circle of anemones they gradually opened in succession. They 

 were found to be unable to localize the direction in which the food 

 was lying. 



Dr. Romanes considers that the sense which is thus shown to be 



* Journ. Linn. Soc. (Zool.) xvi. (1882) pp. 474-G. 



