LUPERINA (?) (aPAMEa) GUENEEI, DOUBLEDAY, AS A SPECIES. 203 



that explain themselves. To return to our nickerlii, the five 

 differences noted by Mr. Pierce might each be dealt with as including 

 several minor points. Amongst others not referred to by Mr. Pierce, 

 I may mention the extension by which the sacculus connects with the 

 further portion of the clasp, joining it at the origin of what I take to 

 be the ampulla of Pierce. This extension is strengthened on its dorsal 

 margin (or near it) by a chitinous rod. This rod in nickerlii is more 

 slender than in testacea and it so happens that this makes it look 

 longer than in testacea, though as a matter of fact, it is if anything 

 rather shorter. At its distal end this rod appears to return along its 

 dorsal margin for a short distance, into the end of a weakly chitinised 

 area. This return portion however in nickerlii (f/neueei) is in fact a 

 distinct piece, of a Avedge-shape, starting from the end of the weaker 

 area. In testacea, on the other hand, it is less chitinised, more fused 

 with the rod below, and its basal end, instead of looking like a totally 

 separate structure as in nickerlii, looks like a short weak finger of the 

 rod pointing across the clasp. These differences are illustrated in 

 Plate IX. 



On the opposite side of the weak space the shaft of the clasp shows 

 three dark lines. These are, I believe, merely folds, due to some 

 peculiarity in preparing the specimens. The same process, however, 

 does not produce this effect in testacea, though curiously enough in 

 one specimen of testacea there seems to be some actual structure on 

 the upper of these lines ; this one I have chosen for figuring, but in as 

 far as this makes it agree with nickerlii, it is an aberration. 



Duinerilii is clearly a closely related species, but not so close to 

 them as testacea and nickerlii are to each other. I take the synonymy 

 to be : — 



nicherlii, Frr. 



var. pueneei, Dbl. {incerta, Tutt). 



ab. baxteri, South. 



ab. fusca, Turner. 



ab. minor, Turner. 



ab. murrayi, Turner. 



ab. iota, Turner. 



It seems to me that Mr. Turner does not quite correctly present 

 Mr. Banks' views on the value of the genitalia for specific determin- 

 ations. From his article I gather that his views are very like those I 

 have often expressed, viz., that if the genitalia markedly differ, then 

 we have two species. If they appear to be alike, it does not follow 

 that two forms are one species, and is only conclusive evidence to that 

 effect for those who already believe them to be one species. I may 

 say, however, that I have never myself seen two unquestionably 

 distinct species with identical genitalia, and suspect that a closer and 

 more minute scrutiny would give a different aspect to reported cases. 



In the case we have in hand the differences between nickerlii and 

 testacea would abundantly separate them were they otherwise supposed 

 to be onlj' one species, whilst the identity of the appendages in nickerlii 

 and ijueneei proves them to be only one species, because the case for 

 believing them to be two species is of the very weakest. As geo- 

 graphical varieties, their differences either in the genitalia or otherwise 

 is much less than is very common between the geographical varieties 

 of other species." 



Since receiving the above remarks from Dr. Chapman I have been 



