511 TIIITICELLIDJE. 



DALYELI/S description of T. flava is not sufficiently 

 minute, nor his figure sufficiently trustworthy in details, 

 to enable us to form a satisfactory judgment as to the 

 form which he had in view. Mr. Norman, who has ob- 

 tained the T. Korenii of G. O. Sars in Scotland, is of 

 opinion that it is identical with the present species. He 

 considers the length of the peduncle comparatively un- 

 important as a specific character ; whilst the fact that all 

 the Scottish specimens were attached to the same kind of 

 Cirriped affords a presumption that they are referable to 

 the same species. On the other hand, it may be said that 

 the habitat cannot certainly be accounted conclusive evi- 

 dence of identity, and that (though there may be consi- 

 derable diversities in the length of the peduncle within 

 the same colony) the fact that in a large 'group of T. 

 flava (containing thirty or forty cells), as stated by Sir J. 

 Dalyell, the peduncle was always only about half as long 

 as the cell, and the maximum length therefore much less 

 than in T. Korenii, may possibly indicate a difference of 

 species. 



I would not be understood as giving any decided 

 opinion on the point ; but under all the circumstances it 

 seems better to keep the forms apart and retain the two 

 names, if only to challenge further investigation. 



Dalyell says that " the cell is apparently somewhat of 

 membranaceous texture; it becomes distorted, and it stands 



awry on its pedicle The form of the cell bears 



some resemblance to a grain of wheat." 



HABITAT. On Sacculina carcini (a Cirriped parasitic 

 on the common shore-crab, Carcinus mcenas] . 



LOCALITY. Scotland (Dalyell). 



