ON A SPECIES OF SIPHONOPHORE OBSEEVED AT PLYMOUTH. 213 



examination of tbem, but have seen enough of them to know that 

 they do not invalidate the identification of the genus. 



c.s ns 



- Lli 



a 



en 



Fig. 1. — Muggisea atlantica, seen from 

 the ri^rht side. 



F,j 2 



Fig. 2. — The same from the ventral 

 side. 



-CS 



a, siphosome or common tubidar stem, bearing eu, cormidia or groups of zooids at 

 intervals; co, oleocj'st ; cs, somatocyst; n, nectocal.yx ; ns, nectosac or cavity of the 

 nectocalyx ; tii, hydroecium, cavity from the apex of which the siphosome depends. 



Only one species of Muggisea has been adequately investigated ; 

 two others are mentioned by Haeckel^ but they have not been suffi- 

 ciently described. The first species is described by Dr. Carl Chun 

 in a paper in the Sitzungsberichte der k. preuss, Akad. der Wissen- 

 schaften. translated in Ann. and Mag. Nat. Hist., 5th series, vol. xi, 

 p, 153. It was originally desci'ibed as Diphyes KocJiii, and after- 

 wards as Muggiaja. Chun adopts the name Mugrjisea Kochii. 

 This species was obtained at Trieste in the Adriatic, and by Chun 

 at Malaga on the coast of Spain. It is obviously difi^erent from the 

 Plymouth species, for although its shape is similar, its size about the 

 same, and the ridges of the nectocalyx are smooth, the hydroecium 

 is much shorter, and the somatocyst only extends to half the height 



NEW SERIES. VOL. 11, NO. HI. 17 



