10 BRITISH FOSSILS. 



and Eurypterus, and establishes six species of the former genus, 

 whose structure and affinities are discussed in my own note. 

 Subsequent investigation has confirmed the views therein taken of 

 the carapace, its eyes, the chelate antennae, the swimming feet, the 

 general structure of the body, and the absence of abdominal or 

 thoracic appendages ; nor has it, as yet, been absolutely proved that 

 there were more than three pairs of cephalic appendages ; but the 

 basal joints of the ectognaths were mistaken for mandibles, and 

 their connexion with the long palp-like swimming foot was not 

 observed. Neither the epistoma nor the metastoma (the latter is 

 figured in the restoration as a "scale-like appendage") were 

 determined. In inquiring into the affinities of Himantopterus, I 

 compared it successively, with the Phyllopoda, the Pcecilopoda, the 

 Copepoda, and the grounds on which I objected to refer it to either 

 of these orders seem to me still, substantially, to hold good. I then 

 proceeded to compare it with the Cumoid Crustacea, with certain 

 Stomapoda, and with the embryonic forms of the higher Crustacea, 

 and I concluded by expressing the opinion, that " the nearest 

 approach to Himantopterus which could be constructed out of the 

 elements afforded by existing Crustacea, would be produced by 

 superinducing upon the general form of a Cumoid crustacean, such 

 a modification of the appendages as we find among the Zoceiform 

 Macruran larvse."* 



In his " Advanced Text-Book of Geology," p. 135 (1856.) Mr. Page 

 gives a figure of one of the specimens on which Himantopterus 

 was based, and provisionally admits that genus, adopting the 

 " Cumoid " affinities which I had suggested. He considers that those 

 palaeozoic Crustacea and their allies exhibit, "as it were, an interfu- 

 sion of phyllopod, psecilopod, and decapod of brachyurous, macrou- 

 rous, and xiphosurous forms," and figures and names " Slimonia " 

 and < Stylonurus" which he considers to be new genera, but which 

 are not as yet proved to be other than species of Eurypterus and 

 Pterygotus. 



Mr. Salter communicated to the meeting of the British Association, 

 in 1856, a paper " On the great Pterygotus (seraphim) of Scotland, 

 and other Species/' containing his opinion as to the identity of the 

 genera Himantopterus^ and Pterygotus, and some of the farther 

 anatomical facts which had at that time been elucidated. 



* Mr. Salter has misunderstood me, when he says at the end of his memoir (I.e.) that I 

 consider Himantopterus to be " one of the Stomapoda." On the contrary, I have always 

 heen prepared to admit the ordinal distinctness of the Eurypterida. 



f The name Himantopterus could in no case have been retained, as it has been already 

 used for a genus of lepidopterous insects. 



