THE CIRRIPEDIA 



119 



mouth-parts are normal, and the cirri are all present, but are composed 

 of a restricted number of segments. The alimentary canal is com- 

 plete, and in some cases even vestiges of the ovaries have been 

 found. In a second group, comprising »S^. vulgare, S. gigas, etc., the 

 peduncle and capituluni are no 

 longer distinct, and the capitular 

 plates are vestigial (Fig. 69, B). 

 The mantle - cavity is greatly 

 reduced, and the cirri are re- 

 presented by six pairs of unseg- 

 mented processes each carrying 

 two or three long setae. The 

 gut ends blindly. In a third 

 group of species, represented by 

 S. stromii, >s'. rcluiitium, etc., the 

 capitular plates have entirely 

 disappeared and the structure is 

 still further degenerate (Fig. 69, 

 C). It is among the species of 

 the third group that complete 

 separation of the sexes occurs, 

 the large individuals being quite 

 devoid of male organs. 



The degree of degeneration 

 exhibited by the males appears 

 to be correlated, to some extent, 

 with tlieir place of attachment to 

 the female or hei'maphrodite in- 

 dividuals. The less - modified 

 males are lodged in fossettes in 

 the margin of the mantle, while 

 in those species where the modi- 

 fication is more profound the 

 males are attached within the 

 mantle- cavity below or behind 

 the adductor muscle. . , 



T r; J 1 1 /Ti- >- \ ■ ^' u"'aif male of Ihln tjitodrivnlvis. Cc, 



In lola the male {b Ig. / 0) is duct of cement-tjland ; C.K, terminal part of 



Tv.rAri;fir.^l i.^ ., w^ov^r,^,. c^rvi«..,l,.,f vus fleffifiis ; t';), reduced mantle-cavity ; A\ 



modified in a manner SOmewfiat stomach; Gx, brain; au, cement-glands- 



difterent from that obserA-ed in 'i-:'-"'' sub- oesophageal ganglion ; 0, eye ; 



c 1 n mi 1-1 ' oesophagus; iJ, rectum ; Te, testis; V.x, 



OCalprllnm. Ihe peduncle is long seminal vesicle; c, cirrus of last pair. B, 



„ 1 .1 .1 • .1 11 postc-iior end of body with caudal furca. 



and the mantle is greatly reduced (From Gnneis Momorophw.) 



and does not enclose the body. 



The mouth-parts are normal, but there are only two pairs of uni- 



ramous cirri. The alimentary canal is complete. The penis is 



short, in correlation probal)ly with the length and flexibility of the 



peduncle and also with the place of attachment of the males, 



