Prof. R. Kossmann on the Cryptoniscidai. 5 



What from the first caused the greatest difficulty was 

 the ascertainment of the sexual relations. The form first 

 described by Rathke with eyes and natatory feet has been 

 interpreted sometimes as the male, sometimes as the larva. 

 Rathke himself evidently regarded his animal as adult, but 

 without deciding any thing as to its sex. Dana took the 

 corresponding form, which he found in Greusia^ for a male, 

 but made no remark about its age. Lilljeborg's discovery 

 proved that the animals described by Rathke and Dana were 

 young forms ; and it seemed to Lilljeborg impossible to regard 

 them as young female forms, because, although already settled 

 upon the host, they showed no commencement of the trans- 

 formation into the adherent female form. He further com- 

 pared them with the youngest male Bopyrides found by 

 Kroyer, and came to the conclusion that they were immature 

 males. Buchholz regarded this same form (from Balanus 

 balano'ides) as an old larva without recognizable sex ; he 

 found no males, but at the same time declared that the sexually 

 mature animals [Gryptothir balani) found by him were deci- 

 dedly not hermaphrodite. Spence Bate, who had already 

 seen and named the young animal *, thought, in 1868 f, it 

 might perhaps be a male, and adds to the word " immature " 

 a note of interrogation within brackets. He therefore doubted 

 as to the immaturity of the animal, but without in any way 

 ])roving that it was a male, still less a mature one. 



Lastly, Fraisse J asserts with almost perfect certainty that 

 the copulation must take place " in the stage preceding- 

 attachment," and accordingly describes both male and female 

 animals of this stage (representing Rathke's Liriope)^ of 

 which, however, he regards only the former as sexually 

 mature. But his proof would not satisfy most readers. 

 Thus, as regards the males, the testes are scarcely indicated 

 in Fraisse's figure ; their form, aperture, or even structure he 

 has not described at all ; the semen, which was squeezed out 

 by crushing the animal, is not removed beyond the reach of 

 doubt, on account of the mode in which it was obtained and 

 the statements as to the form of its elements, and indeed it is 

 rendered absolutely suspicious by the fact that Fraisse sup- 

 posed he saw it also in the body-cavity of the female attached 

 to the ovaries, where its presence may be pronounced to be 

 impossible. Fraisse found these supposed males swimming 



* Speuce Bate, ' Report of the British Association,' 1860, p. 225. 



t Speiice Bate and Westwood, ' History of the British Sessile-ejed 

 (hiistacea,' vol. ii. p. 267. 



\ Fraisse, " Die Gatlung- CryplvnisvusP he. cit. p. 23, Taf. xv. fig's. -SO 

 aud 32. 



