92 ATEACTYLID^. 



bell is represented as slightly produced and pointed at the 

 top ; and though in a subsequent figure it is rounded, it is 

 fair to infer that this diversity arose from his having had 

 the two forms under observation*. The variation I cannot 

 regard as of much importance. 



Nor is the difference in the length of the peduncle which 

 supports the gonophore in itself a point of greater moment. 

 These slight variations, if constant, might fairly be taken 

 account of along with other distinctive characters ; but as 

 the sole criteria of the species they seem to me to be insuf- 

 ficient. 



Prof. Allmaii also refers to the entire absence in his 

 species of the two smaller tentacles, at the time of liberation. 

 But Dr. Wright's latest note on his species implies that, 

 in some instances at least, they are not developed on the 

 gonozooid of P. repens till a subsequent period ; and, as I 

 have often observed (in the case of Podocoryne cameo), 

 there is very great diversity in the time at which the mem- 

 bers of the second set of tentacles make their appearance. 



From these considerations, and desiring to avoid the 

 undue multiplication of species, though I must always dis- 

 sent from Prof. Allman's judgment with hesitation, I pre- 

 fer to rank P. minutus as a synonym of P. repens. 



Hub. On Sertularians and the Spider Crab, Firth of 

 Forth (T. S. W.) : on Dentalium entails, the operculum of 

 Fusus antiquus, and other shells, from the fishing-boats, 

 Cullercoats (J. A.) : (P. minutus) " forming a fringe round 

 the edge of the operculum of Turritella communis, dredged 

 in Busta Voe, Shetland. Out of between twenty and 

 thirty specimens of living Turritella examined, not one 



* I have a characteristic drawing of P. repens by Mr. Alder, representing 

 the reproductive bodies in situ, borne on short peduncles. It is accompanied 

 by a figure of the free zooid, in which the umbrella is distinctly produced 

 and conical at the .summit. 



