14 FOSSIL CIRRIPEDIA. 



CHARACTERES VALVARUM IN SPECIEBUS FOSSILIBUS. 



Carina angusta^ introrsiim arciiata, ah apice ad marginem hasalem paululum dilatata ; 

 parietes valde injlexi, costis manifestis a tecfo plerumque disjuncti ; in multis speciehus 

 intra-parietibus instriicii : intra-parietcs nonminquam superne prodacti ultra Umbonem, 

 qui Jit inde subcentralis : parietum linea incrementi pcrobliquce. Scuta plerumque 

 subconvexa et tenuia, trapezoidea ; marginibus tergalibus lateralihusque angulo insigni 

 disjunctis. 



Sect. f. Subcarina adest (solummodb species recentes). 



Sect. ft. Subcarina deest. 



A. Valvce quatuordecim : Carina mnbone subceritrali. 



B. Valva duodecim : Carina umtjone ad apicem posito. 



Valves 12 to 15 in number. Latera of the lower whorl, four or six, with their 

 hues of growth generally directed towards each other. Sub-rostrum^ very rarely present. 

 Peduncle squamiferous, most rarely naked. 



CHARACTERS OF THE VALYES IN FOSSIL SPECIES. 



Carina narrow, bowed inwards, widening but little from the apex to the basal margin, 

 having parietes much inflected, and generally separated by distinct ridges from the 

 tectum, and having in many species intra-parietes, which are sometimes produced 

 upwards beyond the umbo, so as to make it sub-central ; lines of growth on the parietes 

 very oblique. Scuta generally only slightly convex and thin, four-sided, the tergal and 

 lateral margins distinctly separated by an angle. 



Sect, f . Subcarina present. (This section includes only recent species.) 



Sect. If. Subcarina absent. 



A. Valves fourteen in number ; Carina with the umbo subcentral. 



B. Valves twelve ; Carina with the umbo at the apex. 



The first of the above two paragraphs contains the true Generic description (here leaving 

 out the softer parts), as applicable to recent and, as far as known, to fossil species : the 

 second paragraph has been drawn up to aid any one in classifying the characteristic valves, 

 when found separated, as is most frequently the case with all fossil Pedunculata. The first or 

 proper Generic characters would have been more precise, had it not been for the existence of 

 one recent species, the S. villosum [Pollicipes villosus, Leach, Calentica Homii, J. E. Gray,) 

 which leads into -the next genus Pollicipes. I mention this species in order to confess, that 

 had the valves been found separately, and their number unknown, they would certainly 

 have been included by me under Polhcipes, although, taking the whole organisation into 

 consideration, I have determined to include this species under Scalpellum. I need not 



' The meaning of this and all other special terms is given in the Introduction at p. 9. 



