IH87.J 



PROF. HOWES ON PALINURUS PENICILLATUS. 



4G9 



faceted inner free border, and that it had all the characters and 

 relations of an endopodite. 



If this were so, and if the liomology between a typical appendage 

 and the eye-stalk w<is accepted, the eye-bearing (corneal) portion was 

 clearly esopoditic in position, and it became a question as to how 

 far it might, or might not, represent that segment of the typical 

 appendage ^. 



Cephalon oi Palinurus penicillatus, bearing an antenniform ophthalmite. 



Prof. Howes held that the only logical conclusion which could be 

 drawn from the study of the specimen was that it supported what 

 M. Milne-Edwards tersely calls, " les vnes theoretiques relatives a la 

 similitude fondamentale des parties susceptibles de revetir des 

 caracteres difPe'rentes " ". 



' The only reference to this specimen made by subsequent writers was one by 

 Eolleston in his remarkable work ' Forms of Animal Life.' Dealing with the 

 eyes of Crustacea, Prof. RoUeston had cited it as an example " of the occasional 

 replacement of their facets by a flaseUuni sucli as the antenme carry." This, 

 Prof. Howes had ascertained from M. Milne-Edwards, was a misinterpretation 

 of the original description, the cornea and flagellum being, in reality, discon- 

 tinuous. 



^ The ' Challenger ' Eeports liave recently brought to light the following. 

 Sars has shown that, among tlie Sehizopods, highly organized luminous organs 

 appear (ex. Etiphasia) at the bases of certain appendages and elsewhere; con- 

 cerning those of tlie appendages, it is significant to find that they are boi-ne 

 upon the eye-stalks in addition to the true visual organs, and that in a position 

 identical with those of the post-oral series. Beddard records in the Isopods 

 Arcturus, Asiriiriis, and Mimna a condition essentially intermediate between 

 the typically Edriophthalmous and Podophthalmous types.— G. B. H. 



