Curious Cumacea. 187 



shows on the carapace an amusing likeness to the 

 human countenance. It is not at all uncommon, and 

 its habit of holding the tips of the antennae just out 

 of the sand had been before noticed, but the meaning 

 of this behaviour was now for the first time explained. 



At the next meeting Mr. Robertson exhibited a 

 new crustacean from Cumbrae, to which Mr. Spence 

 Bate, on its being sent to him, gave the name Cuma 

 unguiculata. 



At this period the cumacea, the group of crus- 

 taceans to which this new species belonged, had been 

 very little studied, and very little was accurately 

 known about them. Some men of science, whose 

 word at the time was almost law, had declared them 

 to be creatures not full grown, larval forms, while 

 other naturalists had rightly shown that they were 

 adult. There was also a controversy whether they 

 had eyes or no eyes, the fact being that some are 

 blind, while others have eyes. Of the latter set the 

 eye is generally single and central, whereas in Mr. 

 Robertson's species, now known as Nannastacus 

 unguiculdtus (literally, dwarf lobster equipped with 

 nails), there is a pair of widely separated eyes, which 

 is a very exceptional character in this group. 



By ordinary observers the cumacea would be con- 

 sidered rare animals and difficult of capture, yet by 

 methods which will be subsequently described they 

 may in the proper localities be taken by hundreds. 

 Between 1859 and 1889 Mr. Robertson was able to 

 show that there were at least thirteen distinct species 

 in the fauna of the Clyde alone. 



Dr. Anton Dohrn, now for many years past director 



