446 E. KAY LANKESTER. 



h. " Off Cape St. Vincent, Station 25 ; Porcupine, 1870 ; 374 

 fathoms." [One specimen of normal form. — E. E. L.] 



c. ^'Porcupine, 1869 j Stations 1, 2, S, 8; 106—808 

 fathoms. Off S.W. Ireland." [Seven specimens of normal 

 form.— E. R. L.] 



d. " Holtenia ground, Porcupine, 1869; Stations 47a and 

 88 ; 542 and 705 fathoms." 



[Three specimens of the form with modified eye-stalks 

 and rostrum (see PI. 34, figs. 8, 10, 11). These are the 

 specimens referred to by Canon Norman in the extract above 

 given from ' The Depths of the Sea/ and appear to be the 

 only specimens of this form hitherto found. It seems 

 important to point out at once that, so far as actual depth is 

 concerned, the extreme depth of the stations in which the 

 normal specimens were found exceeds that at which the modi- 

 fied form from the Holtenia ground was procured. Female 

 specimens show a length of 4 mm. from the posterior margin 

 of the carapace to the base of the rostrum ; male specimens 

 are as small as 24 mm. in the same dimension. — E. R. L.] 



It will bo obvious at once that Dr. Norman only described 

 two forms of his Ethnsa granulata — both of them blind; 

 but whilst the one still retained a corneal area on the eye 

 peduncle, the second form had lost this character, and the 

 eye-stalks had become immovable and more or less pointed 

 (see Pis. 33 and 34). 



It is, therefore, remarkable that Lord Avebury should speak 

 in the paragraph cited at the commencement of this memoir 

 of three forms, adding a form 'Hiving near the surface" and 

 having " well-developed eyes." This third form has not yet 

 been discovered in the genus Cymonomus, but Lord Avebury 

 is quite right in principle, since there is no doubt that such a 

 shallow-water form has existed, and very possibly still exists. 

 In other genera closely allied to Cymonomus — for instance, in 

 Cyclodorippe nncifera, Ortm.— a form from a depth of 

 fifty metres is described (Doflein, ' Biol. Centralblatt,' August, 

 1903) with well-pigmented eyes and longer eye-stalks; whilst 

 in specimens of the same species from a depth of 700 metres 



