MODIFICATION OF THE EYE PEDUNCLES IN CYMONOMUS. 445 



quote fi'om a preliminary notice of the Crustacea by the Rev. 

 A. Merle Norman — "Etliusa granulata (sp. u.), the same 

 species as that found off Valentia, but exhibiting a most 

 extraordinary modification of structure. The examples taken 

 at 110 — 370 fathoms in the more southern habitat have the 

 carapace furnished in front with a spinose rostrum of 

 considerable length. The animal is apparently blind, but 

 has two remarkable spiny eye-stalks, with a smooth rounded 

 termination where the eye itself is ordinarily situated. In 

 the specimens, however, from the north, which live in 542 

 and 705 fathoms, the eye-stalks are no longer movable. 

 They have become firmly fixed in their sockets, and their 

 character is quite changed. They are of much larger size, 

 approach nearer to each other at their base, and, instead of 

 being rounded at their apices, they terminate in a sti-ong 

 rostrate point. No longer used as eyes, they now assume 

 the functions oE a rostrum; while the true rostrum, so 

 conspicuous in the southern specimens, has, marvellous to 

 state, become absorbed. Had there been only a single 

 example of this form procured, we should at once have 

 concluded that we had found a monstrosity ; but there is no 

 room for such an hypothesis by which to escape from this 

 most strange instance of modification of structure under 

 altered conditions of life. Three specimens were procured 

 on two different occasions, and they are in all respects 

 similar." 



The specimens thus described are those now before me — 

 forming part of the Norman Collection acquired hj the 

 trustees of the British Museum, They have, until now, not 

 been figured or further described, and are therefore practi- 

 cally unknown to carcinologists. They are preserved in 

 alcohol in separate tubes, labelled as follows : 



a. "Porcupine, 1869; Stations 24, 29, 30; 109 to 1380 

 fathoms. Between Ireland and Rockall." [These are two 

 specimens of normal form as drawn in PI. 33, fig. 2, of the 

 present memoir. — E. R. L.] 



