Miscellaneous. 429 



where be says, " In regard to the Crustacea called Cumce, I casnot 

 say positively that the group must as a whole be suppressed. But 

 I can state \\i{\\ confidence, that all the species of that genus which 

 I have had an opportunity to examine alive — and I have watched 

 three — are young of Valfemon, Cranyon and IJippohjtcy Trof. 

 Agassiz, in a recent letter (to J. D. Dan.% dated Nahant, July 18th) 

 respecting these observations of Mr. Bate, writes that "thev only show 

 how extensive a field of observation remains untrodden among these 

 little forms. Had Mr. Bate looked more fully into the embryology 

 of Crustacea, he would have been better prcj)ared to appreciate the 

 close correspondence there is between the young of certain families and 

 the adults of others, and would have known that these facts are not 

 limited to the Macroura, as I have shown in my Lectures on Embryo- 

 logy, p. G2-G9 : ho would know that the eyes of even the highest 

 Crustacea are sessile in the young, &c., and that such characters ob- 

 served upon young Crustacea do not therefore prove them to be peculiar 

 types, unless at the same time their reproduction be satisfactorily 

 traced. Acknowledging Mr. Bate's interesting observation as proving 

 that his Diastylis liathJai is an adult animal, the question has made 

 a real progress through his researches ; but it remains as certain as 

 before, that there are Cumce ivluch are larvce of 3Iacroura." — Silli- 

 ina?is American Journal, Sept. 1856. 



NOTE ON CALLITRICHE HAMULATA. 



To the Editors of the Annals of Natural History. 



October 13, 1856. 



Gentlemen, — "While lately in Scotland I had the satisfaction of 

 finding the Callitriche humvlata (Kiitz.) growing in a ditch commu- 

 nicating with the river Annan, close to Jardine Hall. 



The specific character of the C. pedunculata, as given in Babington'g 

 Manual (ed. 4. p. 293), applies accurately to the C. hamulata, with 

 the exception of the supposed want of bracts in the former plant. 



On mentioning the subject to Mr. Babington, he infonned me that 

 he had detected bracts on cultivated plants of his 6'. pedunrulata, 

 ft. sessilis, and convinced himself that that plant is C. hamulata. He 

 considers C. hamulata (Kiitz.) as the type of the species, and the 

 C. pedunculata (DC.) to be a variety of it. 



^ly discovery does not therefore increase the number of our spe- 

 cies, but only corrects the nomenclature by identifying a doubtful 

 plant with a known continental species. This is a highly satisfactory 

 result. 



I may add that Mr. Babington mentioned that the bracts are 

 usually very deciduous in this plant ; such I found to be the case in 

 the Scottish specimens. 



I am, Gentlemen, yours obediently, 



Frederick Townsend. 



