35 



I proceed to describe it at greater length, and to bestow upon 

 it a name which shall distinguish it from its congeners. 



The sub-order of the Ctenostomata, in accordance with the 

 system of classification most recently accepted, is subdivided 

 into the two families of the Alci/onidiadce and the Vesicu- 

 lariada. The first of these is distinguished by the polypi- 

 dom being sponge-like, fleshy, and irregular in shape, and in 

 which the cells furnished with a contractile orifice are im- 

 mersed. In the second the polypidom is plant-like, horny, 

 and tubular, having free deciduous cells, whose extremities 

 are flexible and invertile.^ The species to which I would 

 now direct attention, though possessing the circlet of setse 

 characteristic of the order, secretes a polypidom referable to 

 neither of the two forms just indicated. 



Its affinities with the Vesiculariadce are the most marked, 

 but, as will be seen on reference to the accompanying plate, 

 the contour of the polypidom is entirely irregular, and wholly 

 wanting in that uniformity and complexity of structure so 

 characteristic of that family, possessing neither the main 

 rachis nor the distinct deciduous cells by which all the mem- 

 bers of the Vesiculariadce are so readily distinguishable. 



Hence, it appears essential that another family should be 

 specially constructed for its reception, and, taking into con- 

 sideration the uniform structure of the polypidom, I propose 

 the acceptance of the term Homodiatidce as a family name 

 expressive of that same structure. The diagnosis of this 

 third family may be briefly summed up as follows : 



Polypidom horny^ tubular ; cells not deciduous nor sepa- 

 rately distinguishable, but throughout freely communicating, 

 their terminations flexible and invertile. The generic name 

 I propose for this new polyzoon is Victorella, a somewhat 

 lame acknowledgment of the great variety of aiiimal life which 

 the locality from whence it was procured has afforded me. 

 The same characters above given serve also for its generic 

 distinction, to which must be added that the animal has no 

 gizzard, and is provided with eight ciliated tentacles. 



' In Gosse's 'Marine Zoology,' and in the ' Micrograpliic Dictionary,' the 

 genus Pedicellma is admitted as the representative of a third family of tiie 

 Ctenostomata, but the error of such an arrangement becomes apparent on 

 considering that the individual animals in the various species of this genus 

 simply roll up their tentacles when at rest, and are unable to withdraw them 

 within their polypidom ; and hence the crown of protective setai sur- 

 rounding the orifice of the cell and cliaracf eristic of all the true Cleiiostomes 

 would be to them a simple superfluity, and the absence of these character- 

 istic setae, in conjunction with other well-marked structural peculiarities, 

 has furnished ample grounds for setting this genus apart as the type of a 

 separate sub-order known as the Pedlcellinece. 



