XL 



OBSERVATIONS ON THE STRUCTURE AND 

 AFFINITIES OF HIMANTOPTERUS. 



Quart. Journ. of the Geol, Soc, vol. xii., 1856, //. 34-37. 



From what has been stated in the preceding pages, it would appear 

 that the following propositions embody all that is at present certainly 

 known with regard to the great structural features of the genus 

 Hiinan top terus. 



1. The body is composed of a comparatively small carapace, suc- 

 ceeded by eleven or twelve free segments, the last of which is bilobed, 

 lanceolate, or wide anteriorly and acuminated posteriorly. 



2. At the margin of the carapace on each side lies a rounded or 

 oval eminence, which there is every reason to regard as an eye. 



3. The free segments have no appendages. The cephalothorax 

 presents three pairs : an anterior, probably chelate pair, occupying 

 the position of antennae ; a middle pair of broad, short, foliaceous, 

 serrated organs, which have the appearance of mandibles ; a posterior 

 pair of long flattened, jointed appendages, terminated by an oval 

 palette, and not improbably having an articulated filamentous ap- 

 pendage attached to their penultimate or ante-penultimate joint. 



4. Lastly, many parts of the body of Himantopteriis present a 

 peculiar imbricated sculpture, resembling that exhibited by Pterygotus. 



Assuming these data to be correct, the question is, — In what group 

 of animals can we find an analogous structure ? and there are obvious 

 reasons for at once narrowing the field of inquiry to the Crustacea, 

 and confining the search to the different subdivisions of that great 

 group. 



Analogies, if not for Himantopterus, at least for the very closely 

 allied genus Euryptei-us, have been sought by different naturalists 

 among the Pcecilopoda, the Phyllopoda (particularly Apus), and the 



