CliYPTOPHIALUS MINUTUS. 573 



bristles, together forming a flattened brush : this organ is 

 remarkable from the apodeme (a) being bent into the shape 

 of a scythe, with the terminal or blade-portion a little ex- 

 panded, and directed backwards and inwards. The Outer 

 maxilla are sub -triangular in outline, with several bristles on 

 their summits and along their outer surfaces. 



Segments of ~Body. — I have stated that the mouth is 

 succeeded by eight segments. As in all the cirripedes 

 hitherto described, the body consists of only six segments, 

 the number eight at first seems very improbable, and there- 

 fore I may be permitted to state that both Dr. Hooker and 

 myself, when first examining this animal, and having no 

 notion whatever regarding its homologies or the structure 

 of other cirripedes, came to the conclusion, judging only 

 from external appearances, that is, from the transverse 

 folds, and from the lines of movement when the body was 

 bent by a needle, that there were really eight segments. I 

 have since carefully looked to this point : when the outer 

 membrane is cleaned and examined, the four posterior seg- 

 ments are very plain, owing to a dorsal medial line, being 

 alternately either thickened and coloured yellowish, or thin 

 and colourless : the four anterior segments are less plain, 

 but yet the membrane on the dorsal surface, on the line of 

 each fold or articulation, does present some difference, from 

 being destitute of the fine, transverse, toothed scales which 

 occur on other parts. But I lay most stress on the fact, that 

 all these eight articulations were used for the attachment 

 of muscles. Hence I conclude that the eight segments are 

 real ; and we shall see, in the next order, that the very same 

 eight segments are as plain in Proteolepas, as in the larva 

 of an insect or as in an annelid. There is good reason to 

 believe that the general covering or carapace consists in all 

 cirripedes of the three anterior segments, and that the mouth 

 (judging from its appendages) also consists of three segments, 

 consequently the first segment of the body in Cryptophialus 

 must be the seventh or last cephalic segment, and the seven 

 next free segments must be the normal seven thoracic seg- 

 ments. 



The first segment of the body (i. e. last cephalic, fig. 5, 1) 

 is, as stated, the largest, and is attached dorsally to the 



