670 DESCRIPTION OF PLATE, 29. 



Fig. 1, (candj), flexor and extensor muscles, apparently moving the 

 lower segments of both rami, as a whole ; the lower arti- 

 culations in these rami being confluent. 



(e and/ 1 ), flexor and extensor muscles extending up both rami 

 (those only in the near ramus being figured) to their tips. 



(ff) (if)> flexors of the separate segments in both rami. 



Qi), basal articulation of lower segment of the pedicel. 



(/), upper articulation of lower segment of the pedicel. 



(A 1 ), upper articulation of upper segment of pedicel. 



2, Fourth cirrus of Acasta sulcata. 



(i), upper articulation of the lower segment "\ rpj . l *t . 



of pedicel . . . I ' ' , . ' „ ., 



/7N r ix- nj.j . >■ apn/y to all the 



(A), upper articulation or the upper segment I J , i / - 



of pedicel . . . J J * ' 



(I), curved teeth on the pedicel. 



{in), „ „ on the segments of the anterior ramus. 



3, Third cirrus of Chthamalus antennatus. 



4, Second cirrus of Balanus perforatus, viewed exteriorly and 



laterally. 



5, Third cirrus of Xenobalanus globicipitis. 



6, Sixth „ ,, „ 



7, Spermatozoa (copied from Mr. C. Spence Bate, in ' Annals and 



Mag. of Natural History' (S. 2), vol. viii, PL VIII). 

 («), of Verruca Stromia, in an early condition. 

 (b), of Balanus balanoides, more mature, 

 (c), of Balanus perforatus, apparently mature. 



8, Larva of Scalpellum vulgare, immediately after coming out of 



the egg, seen on the ventral surface (letters of reference 

 given below). 



9, Larva of Balanus balanoides, immediately after coming out of 



the egg, seen on the ventral surface, copied from Mr. C. 

 Spence Bate's drawing in ( Annals and Magazine of Natural 

 History' (S. 2), vol. viii, Plate VI, fig. 1 (letters of 

 reference given below). 



10, Larva of Chthamalus stellatus, after the first moult, but 



during the first stage, seen on the ventral surface, copied, 

 with some alterations, from Mr. C. Spence Bate's drawing 

 in ' Annals and Magazine of Natural History' (2 Ser.), 

 vol. viii, Plate VIII, fig. 13. 

 (The following letters apply to above figs. 8, 9, 10.) 

 («), eye. 



(b), first pair of antennae, not observed in fig. 9. 

 (//), the same antennae, as yet encased (in fig. 8) within small 



horns, 

 (c), horns, including the second pair of antennae. 

 (d), mouth, probosciformed : in fig, 8, the specimen having 

 been acted on by potash, the oesophagus can be seen 

 within, with the orifice beneath the swelling, which 

 latter perhaps answers to the labrum. 

 (e), first, uniramous natatory leg (homologically the second 

 thoracic limb). 



