286 Miscellaneous. 



swim pretty rapidly, with a constant rotation upon their longitudinal 

 axis. 



The development of the embryo takes place by a gradual widening 

 of the hinder part, which thus acqviires a bell-like form, the stomach 

 becomes much larger, and the oral orifice, which was depressed in 

 the embryo, becomes considerably protruded. On the third day, 

 the hinder margin of the bell-shaped umbrella exhibits eight small 

 rounded lobes, at the same time that eight corresponding appendi- 

 cular sacs are developed from the stomach. Shortly afterwards the 

 marginal lobes increase considerably in length, and acquire a some- 

 what quadrangular form, with their margins slightly indented ; and 

 at these indentations the rudiments of the marginal corpuscles {ocelli) 

 make their appearance. At this stage the mouth has become much 

 larger, and makes its appearance at the extremity of a short tubular 

 process, — the rudimentary stalk of the four arms possessed by the 

 perfect animal. The motion of the young animal through the 

 water is slower than at first ; but it is still principally effected by the 

 action of cilia, although the umbrella occasionally expands and con- 

 tracts, producing an undulation of the marginal lobes. 



The further progress of the young Medusa to the condition in 

 which Dr. Krohn first observed it, consists in the growth of the mar- 

 ginal lobes, and especially of the lappets into which they are divided 

 by the central indentation, the disappearance of the cilia, the ap- 

 pearance of crystalline bodies in the marginal corpuscles, the greater 

 development of the base of the oral tentacles, and the diminution 

 of the height of the umbrella. At this period also the whitish 

 coat of the embryo disappears, whilst the urticating organs are 

 developed. 



The author followed the further development of the young Pelayia 

 until it had acquired the eight additional ventricular sacs characteristic 

 of the mature animal and the eight marginal tentacles ; but he ob- 

 serves, that four of these had attained a length equal to the diameter 

 of the disk, whilst the other four were still rudimentary. The stalk 

 of the oral arms was longer and larger, but the arms themselves were 

 but slightly developed. — W. S. Dallas. 



DESCRIPTION OF A NEW SPECIES OF SWIFT. 



Cypselus galil^ensis, Antinori. 



C. Cauda brevissima, subfurcata : corpore nigro-virescente, nitore 

 metallico perlucido: fronte dilute albida: gula et regione supra- 

 caudali albis : pogonio externo primse remigis albo limbato. 



The third part of last year's ' Naumannia ' contains a communica- 

 tion from the Marchese Oratio Antinori, describing this " apparently 

 new Swift," which was discovered by him in Palestine, on the borders 

 of the Sea of Galilee. Two specimens were procured, — Cyj)selus apus 

 and C. melba ; and Hirundo daurica, ritpestris and rustica were breed- 

 ing abundantly near the same locality. Its similarity to a South 

 African species (C. leucorrhous, Steph. ex LeVaill. Ois. d'Afr. 

 pi. 244. fig. 2) is commented upon ; but it is hardly probable that it 



