TAB. IV. 



[A'.B. — A left-hand scutum {fly. 4,/), and a left-hand tergiiyn {fig. 5, J), have been accidentally figured instead uf right- 

 hand valves, as in all the other Figures and Plates ; hence these two hold reversed positions, and in both the occludent margins 

 are to the right, instead of to the left hand.} 



Fig. 1. Pollicipcs unguis; all the figures except (d) are from the same individual, and 



are magnified twice : {d) is of the natural size. 



(a) Carina. (h) Latus of the lower whorl, probably adjoining 

 (6) Tergum, inside view. the carina. 



(c) Ditto, outside view. (i) Ditto, inside view. 



(d) Ditto, ditto, (var., natural size.) (k) Latera of the lower whorl, probably the two 



(e) Rostrum. adjoining the rostrum. 

 (/) ''^ub-rostrum. (I) Ditto, inside view of. 



(ff) Upper latus. 



Fig. 2. Pollicipes validus; all figures natural size. 



(a) Carina. (e) Scutum. 



(b) Ditto, inside view. (/) Ditto, inside view of. 



(c) Ditto, lateral internal view of. (</) Ditto, inside view of another specimen. 



(d) Ditto, section of upper part. 



Fig. 3. Pollicipes gracilis. 



(a) Scutum, natural size. (b) Scutum, magnified, inside view. 



Fig. 4. Pollicipes dorsatus; all figures natural size, except (d), magnified twice. 



(«) Carina, inside view of. (d) Tcrguni, magnified twice. 



(b) Ditto, outside view of. (e) Tergum, natural size. 



(c) Ditto, section of upper part of. (/) Scutum, left-hand valve {vide supra). 



Fig. 5. Pollicipes striatus ; figures natural size, and magnified twice. 



(a) Carina. (b) Tergum ; a left-hand valve (vide supra). (c) Scutum. 



Fig. 6. Pollicipes semilatus ; magnified about ten times. 



Fig. 7. Pollicipes rigidus; all figures thrice natural size, except (/), which is twice 



(a) Carina. (d) Scutum. 



(b) Ditto, side view of. (e) Tergum. 



(c) Ditto, section of lower part of, (/) Scutum, inside view. 



Fig. 8. Pollicipes fallax ; figures twice natural size. 



(a) Scutum. (b) Tergum. * 



Fig. 9. Pollicipcs elegans. 



(a) Carina, thrice natural size. (c) Scutum, twice natural size. 



(b) Ditto, section of. (d) Tergum, twice natural size. 



Fig. 10. Pollicipes Bronnii; figures magnified twice. 



(a) Carina. (d) Carina, section of, at one third of length from 



(b) Ditto, lateral view of. the apex. 



(c) Ditto, section of, near basis. 



Fig. 11. Pollicipcs planulatus; Tergum, upper figure, natural size. 



