Willemoesia Group of Crustacea. 487 



There was no " round black spot " on the base of the pe- 

 duncle of the inner antennse in any of the specimens that came 

 within my observation ; but there is a depression that may 

 correspond with it, and is probably that which Heller noticed, 

 but it is caused by the olfactory tubercle of the second or 

 outer antennse being impacted strongly against the inner. In 

 the basal joint of the inner antenna? I have dissected out an 

 osseous auditory apparatus, which is sufficient itself to deter- 

 mine that this same position cannot be occupied by an organ 

 of sight. 



The third set of questions evidently shows that my paper 

 was read for the sake of criticism. I never said or thought 

 that Polycheles was related in any way to Alpheus. I 

 merely paralleled the development of the eyes in the two 

 genera and the probable similitude of adult existence ; and 

 the Rev. A. M. Norman further adds, with a note of ad- 

 miration to give it the more weight, " that the embryos 

 of both have ' large and distinctly pedunculated eyes,' a cha- 

 racter which, I take it, is not very rare among the embryos of 

 the Macrurous Crustacea!" My remarks were in relation to 

 adult forms with '' depauperized organs of vision ;" and there- 

 fore the Rev. A. M. Norman's remarks do not bear on the 

 subject unless he knows the embryonic form of ^4 stocks ? 0a- 

 leucus ( Willeraoes-Suhm) , Nephrojjsis Stewartt (Wood-Mason) , 

 and the blind prawns of the North-American caverns. 



With regard to the fourth set of questions, which relate to 

 Eryon^ I offer no opinion, but hope to be able, at no very dis- 

 tant date, to avail myself of the best opportunities at my com- 

 mand ; in the meantime I cannot help remarking that all the 

 notes on which the Rev. A. M. Norman lays so much stress are 

 but negative in character. 



However, I am much obliged for having my attention di- 

 rected to points which I hope will enable the Rev. A. M. 

 Norman to determine the sexual character of his own specimens 

 of this group ; and I can only add that I should have done it 

 with more pleasure had the Rev. A. M. Norman's paper been 

 written less in the style of a categorical examination. 



Lesteigonus. 



With regard to the notes relating to Lestrigonus the rev. 

 gentleman has gone out of his way, and shows the character of 

 his criticisms. He says, " There is another case, however, in 

 which Mr. Bate persists against proof in maintaining a genus 



founded on mere sexual characters ; but all other car- 



cinologists are, I believe, agreed that Lestrifjnnns is simply the 

 male of Hyperia ; and I have myself paired the British species." 



