14 Prof. R. Kossmann on the Ciyptoniscicloe. 



and the fore part of the body outside in the open. I have 

 been unable any longer to detect antennas or buccal organs in 

 the stage of female maturity, and my experience was similar 

 in some other genera. Among these are Eumetor^ which 

 was likewise discovered by me in 1872, and has now been 

 more accurately studied, and Cahircyps^ which inhabits the 

 brood-cavity of the Bopyridse, its nearest allies. All these 

 three genera, in the adult condition, have the head free, and 

 consequently need then no apparatus for fixation or boring. 

 It is true also that they can then take no more nourishment. 

 But this is no longer necessary to them ; G ryptoniscus and 

 Zeuxo also at this time take no more nourishment, although 

 they have the head still inserted into the blood of the host. 

 This follows with certainty from the retrogression of the 

 digestive apparatus, already ascertained by Fraisse in Gnjpto- 

 niscus. 



The knowledge of the nature of this digestive apparatus 

 has advanced by various roundabout ways ; 1 will here only 

 briefly refer to its course hitherto. Rathke* ascribed to the 

 Bopyridas a liver consisting of seven pairs of follicles opening 

 separately into the intestine ; Cornalia and Panceri f, certainly 

 in a difierent genus, describe, instead of these fourteen folli- 

 cles, two tubes running parallel to the intestine, their opening 

 into which they did not see. Buchholzf found in Crypto- 

 niscus halani, intercalated between the oesophagus and the 

 rectum, a comparatively enormous vesicular reservoir, drawn 

 out posteriorly into two caica, which, from its appearance, is 

 " really to be regarded as the intestinal canal ;" and a similar 

 condition of things in Entoniscus was described first by Fritz 

 Miiller § and afterwards by Fraisse ||, the former characterizing 

 the organ as the liver, the latter as rectum. This latter inter- 

 pretation, as a section of the intestine, is also maintained by 

 Fraisse for a corresponding organ in the Cryptoniscidas, which 

 certainly, by its exceedingly vigorous growth, soon loses all 

 trace of a division into parallel tubes. I have already else- 

 where, with regard to the Bopyrida? and Entoniscidas, adopted 

 the opinion of those who regard this organ as a homologue of 

 the so-called liver of the Crustacea. I do so also uncondi- 

 tionally with respect to the digestive organ of the Crypto- 



* Rathke, ' De Bopyro et Nereide,' 1837, p. 9, tab. i. fif?. 7 b. 

 t Cornalia e Pauceri, " Osservazioni sopra im iiuovo geuere di cro- 

 stacei isopodi sedentarii, Gyye hranchialis,''' 1858, p. IG, tab. ii. fig. 6e. 

 t Bucliliolz, Jlemioniscus balani, loc. cit. p. olO. 

 § Fritz Miiller, JEntoniscus purcellance, iu Ai'chiv f iir Naturg. Bd. xxviii. 



p. 11. 



II Fi-aisse, EtUmiscus Cavolinii, 1878, p. 17 



