106 ANTHOZOA HYDROIDA. 



soon disappears. The ova while in the vesicle are arranged round a 

 central placentular column., and the lid which closes the vesicle is a 

 mere dilatation of this column, which appears to be composed of two 

 pieces soldered together, and bulged at intervals, where perhaps the 

 ova are more immediately affixed in their immature state.* 



The polypes are little regardless of external irritations or in- 

 juries, and readily protrude themselves when submerged. They 

 have from sixteen to twenty-six (Van Beneden says twenty-four) 

 long filiform tentacula inserted beneath and around the oral disk ; 

 and under a good magnifier they appear rough with minute tu- 

 bercles placed in close whorls. The edentulous mouth is in the 

 centre of the tentacula, and assumes the shape sometimes of a round- 

 ed projecting tubercle, sometimes of a narrow column, and some- 

 times of a broad flat disk with a stricture under it simulating a 

 neck. It leads directly to the stomachal cavity, which is large and 

 undivided ; and I have occasionally witnessed within it currents of 

 a fluid filled with minute granules, as has been more fully noticed 

 by Mr. Lister and Dr. Fleming. 



Milne-Edwards, in the belief of there being a specific difference 

 between the zoophytes described by Pallas and Fleming, has pro- 

 posed to call the latter Campanularia Flemingii, distinguished by 

 the cells having an even rim ; whereas it is stated to be serrulated in 

 the other. I have preferred following the judgment of Fleming, 

 who has very carefully studied the species. 



4. L. OBLIQUA, simple, zig-zag t the cells on short stalks, cam- 

 panulate, with the rim deeply sinuated on the proximal side. 

 W. W. Saunders. 



PLATE XXVIII. FIG. 1. 



Laomedea obliqua, Saunders in litt. 5 Jan. 1841. Campanularia, Lister in Phil. 

 Trans, an. 1834, 372, pi. 8, fig. 5. 



Hob. Parasitical on sea-weeds. Brighton, W. Wilson Saunders. 

 The polypidom is affixed as usual by a creeping tubular fibre, 

 from which numerous polypiferous shoots arise in an irregular man- 



The manner in which the gemmules are produced differs in the two species. In 

 L. geniculata " the whole of the granular pulp is formed into the gemmules ; then 

 they escape, leaving the case empty ; in this (L. gelatinosd) there is a central placen- 

 tular column to which the gemmules are attached by an umbilical cord. The polypes 

 are alike in both, and are liable to the same variations and irregularities in the num- 

 ber of their tentacula." R. Q. Couch. 



