FOSSIL CIRRTPEDES FROM NEW ZEALAND. 853 



From a study of the isolated valves here described, it seems 

 reasonable to suppose that they formed a capitulum just as is 

 shown in the restoration (fig. 13). No examples of the carinal 

 and inframedian latera have yet been found, but doubtless these 

 will prove to be somewhat like the valves diagrammatieally 

 indicated in the restoration. The capitulum, as restored, 

 possesses 13 valves, but this number may have been increased 

 to either 14 or 15 by the addition of a I'ostrum or subcarina, or 

 both. In any case, it is apparent from the structure and dis- 

 position of the valves, that the species falls into the group now 

 included in the subgenus Arcoscalpellum Hoek. 



Sccdpellum (A.) tmgulatum may be compared with S. michelot- 

 tianimi Seguenza*, from the Pliocene of Messina, Sicily, and 

 S. quaclraUtm Dixon t sp., from the Eocene of Bognor, Sussex, 

 but both these species differ in the valves being appreciably 

 thinner. 



Although size is often of little account, none of the numerous 

 valves of S. quadratum that I have seen are more than half the 

 size of the largest valves of S. (A.) ungulatum. The carina of 

 aS'. quadratihin differs in having inwardly bent intraparietes, the 

 scutum in having a raised border to the tergal margin, the tergum 

 in the carinal margin being elongately ^-shaped and the apical 

 half bent towards the carina, the upper latus in being more 

 symmetrical and proportionally wider, and the rostral latus 

 differs in the absence of the prominent, transverse, rounded 

 ridge or fold and in the outer extremity of the valve being 

 thickened only to a small extent. 



In S. inichelottianum the carina diffei^s in having broad, 

 rounded, longitudinal ridges on the outer margins of the tectum, 

 in the tectum being proportionally much wider and the basal 

 margin less convex, the scutum in having the tergo-lateral 

 portion of the valve markedly convex and rounded inwards at 

 the tergal margin, the tergum in being much thinner and very 

 much flatter transversely and the median longitudinal ridge 

 hardly perceptible, the upper latus in being more triangular in 

 shape and in the absence of a thick ledge formed beneath and 

 beyond the umbo, the rostral latus in having a much smaller 

 extent of the valve thickened at the outer extremity and in the 

 inner extremity not being obliquely truncated. 



S. niichelottianuTn var. gassinensis Alessandri + (Pliocene to 

 Miocene) agrees more closely ■ with. S. (A.) imgulaturn in having 

 the basal margin of the carina more strongly convex, but the 

 other characters of this and the remaining valves differ quite as 

 much as the valves of S. inichelottianum Seguenza. 



* 1876. G. Seguenza, Atti Accad. Pontaiiiana, vol. x, p. 381, pi. vi. figs. 15-25 ; 

 p. 464i pi. X. fig. 26. 



t 1846. F. Dixon, in J. de C. Sowerby, Min. Conch, vol. vii. pi. 648; 1851. 

 0. Darwin, Pal. Soc. Monogr. Poss. Lepadida?, p. 22, pi. i. fig. 3. 



X 1906. G. de Alessandri, Palajontogr. Ital. vol. xii. p. 252, pi. xiii. figs. 10-15. 



