384 The Naturalist of Cumbrae. 



Isodictya nodosa, Bowerbank. 

 Isodictya involuta, Bowerbank. 

 Isodictya pertenuis, Bowerbank. 

 Isodictya scitula, Bowerbank. 

 Isodictya collina, Bowerbank. 

 Isodictya implicita, Bowerbank. 

 Rhaphiodesma fallaciosum, Bowerbank. 

 Rhaphiodesma intermedium, Bowerbank. 



In the same volume the following species are described : 



Halichondria Robertsoni, Bowerbank. 



Of this Bowerbank says, "The specimen in course of 



description was given by the late Dr. Scouler to Mr. D. 



Robertson, and by him to my friend the Rev. A. M. 



Norman, by whom it was sent to me for examination and 



description." 

 Halichondria condensa, Bowerbank. 



Bowerbank says of this, " Hob. Isle of Man; Mr. D. 



Robertson. This sponge was presented to my friend the 



Rev. A. M. Norman by Mr. D. Robertson, and was sent 



to me for examination." 

 Halichondria coralloides, Bowerbank. 



Bowerbank says of this, Hab. Firth of Forth ; Mr. D. 



Robertson. I received this sponge from my friend the 



Rev. A. M. Norman, to whom it was presented by Mr. D. 



Robertson." 

 Isodictya inaequalis, Bowerbank. 



The habitat is apparently unknown. Bowerbank says, 



" I received a small specimen of this species from my 



friend the Rev. A. M. Norman, who obtained it among 



others from Mr. D. Robertson." 



There are other departments of natural history in which Mr. 

 Robertson's co-operation has been similarly serviceable, but 

 from want of access to the literature of the subjects I am unable 

 to supply the details. There is, for example, reason to believe 

 that the Dr. von Frauenfeld mentioned in Chapter XIV. named 

 a new species of univalve shell in honour of Mr. Robertson. 

 On the other hand, the annelid of the genus Clymene, with which 

 Professor Koelliker was concerned (see page 171), may have 

 been the already-known species, Clymene lumbricalis. 



