52 



SCIENCE. 



[N. S. Vol. XX. No. 497. 



ington. Unfortunately none of the libraries 

 here has been favored with his work, — not 

 even the Smithsonian Institution, which is 

 very liberal in the distribution of its publi- 

 cations throughout the world. It is to be 

 regretted that the scientific institutions in 

 France have not responded to the offer of ex- 

 changes from the Smithsonian Institution and 

 as a result many of their publications are not 

 to be had here. Before the publication of my 

 ' Contributions to the Natural History of the 

 Isopods ' (e), I made every effort to secure 

 Bonnier's work, without success. After wri- 

 ting to other libraries in this country, I have 

 since succeeded in securing the loan of the 

 volume from the Museum of Comparative 

 Zoology at Harvard College. 



With the humility of a disciple, I admit 

 that I was in error (as I discovered before the 

 criticism appeared) in considering that Giard 

 and Bonnier had identified Grapsicepon fritzi 

 with the species of Bopyrus found by Fritz 

 Miiller on an Alpheus (c). The name Bopyrus 

 alphei, it appears, was given by Giard and 

 Bonnier in 1890 (6) to the form found by 

 Miiller on a species of Alpheus, but as no de- 

 scription or figure ever appeared until those 

 I gave in 1900 (d), ten years later, I 

 think no zoologist would quote Giard and 

 Bonnier as the authority of the species, a 

 name without a description or figure not 

 being usually accepted. I do not agree with 

 Professor Bonnier in placing Bopyrus alphei 

 in the genus Bopyrella, for I consider it a 

 true Proiopyrus, where I have recently placed 

 it, the abdomen of the female being segmented. 

 My figure is misleading, as it shows no seg- 

 mentation, but, at the time it was made, I 

 could not distinguish any segmentation in the 

 specimen at hand, which was very transparent 

 and colorless. Since receiving other speci- 

 mens, I have been able to see distinctly the 

 segmentation of the abdomen. In Bopyrella 

 the abdominal segments are all fused. 



During the short time that Professor Bon- 

 nier's work was in my possession, I was not 

 able to examine all that it contains, but I 

 noted the great similarity of my genus 

 Parapenceon to his genus OrUone. I do not, 

 however, consider my genus a synonym of 



Orhione, for it differs in not having the sixth 

 segment of the abdomen of the female pro- 

 duced into pleural lamellas, that segment in 

 Parapenceon being very small and rounded. 

 In the type species of Orhione the pleural 

 lamellse are produced to such an extent that 

 they reach beyond the extremity of the 

 uropoda. The second species of Orhione, 0. 

 incerta, described by Professor Bonnier, dif- 

 fers in this respect from the type species and 

 may come under my genus Parapenceon. The 

 author suggests that the second species of 

 Orhione may represent a new genus. The 

 female of Parapenceon agrees more with the 

 female of Cryptione Hansen than it does with 

 the female of Orhione, but the males in the 

 two genera are very unlike. When the male 

 of Orhione is known, there may be other char- 

 acters to differentiate Orhione from both 

 Parapenceon and Cryptione. At present 

 Parapenceon is quite as distinct from Orhione 

 as Orhione is from Cryptione. 



Urohopyrus Richardson is certainly very 

 close to Paloegyge Giard and Bonnier, but can 

 not be considered a synonym. In the female 

 of Urohopyrus ' the uropoda are a pair of 

 douhle-hretnched appendages attached to the 

 terminal abdominal segment; the inner 

 branches are smaller and more slender than the 

 outer branches.' The female of Paloegyge has 

 small, simple, rudimentary, knob-like uropoda, 

 not lamellar in shape nor elongated so as to 

 extend beyond the terminal segment as is 

 found in Urohopyrus. 



In speaking of the thoracic processes in the 

 adult female of Argeia as not being of 

 epimeral origin, but arising from the posterior 

 portion of the segment, I made the statement 

 that it was incorrect to refer to them as 

 ' lames pleurales.' My idea was not to sug- 

 gest that Giard and Bonnier had confounded 

 the ' lames pleurales ' with the ' productions 

 epimeriennes,' but rather to point out that, 

 in a strict sense, it is not exact to speak of 

 them as ' lames pleurales.' They may be 

 considered as the posterior divisions of the 

 ' lames pleurales,' that view being now gen- 

 erally accepted, the anterior division of the 

 ' lames pleurales ' being placed lateral to the 

 ovarian bosses on the anterior portion of the 



