Dr. Henry Woodivard — On a new Loricula. 497 



Tvidest part ; there are 21 rows, not counting the lost small extremity ; 

 the scales in each row are pointed at their inner end where they unite 

 with the alternate rows of the median lateral series, hut they unite 

 hy a nearly straight suture with the sub-scutal or sub-rostral series. 

 This outer (rostral ?) row (like the carinal row on the opposite side of 

 the peduncle) is only l^mm. broad; the scales are almost rectangular 

 in form and are evidently incomplete at their lower end, only 8 being 

 preserved. Beyond this row is seen yet another series, 1 in number, 

 evidently a second rostral series, belonging to the margin of the lower 

 side of the peduncle, attached to the shell of the Ammonite, as they show 

 the inner surface of the scales slightly displaced, having only a straight 

 suture-line to unite them with the overlying narrow series. 



Writing of the peduncle (p. 82, op. cit.) Darwin says : " The base 

 is sharply pointed, down to which the full complement of scales 

 extends. In each row there are about 21 scales, their number 

 obviously depending on the age and size of the individual " (p. 83). 



We have already pointed out the difference in the number of scales 

 in the three principal series, viz., 23 rows in the carino-lateral, 

 22 in the median, and 21 rows in the scutal series, causing the 

 very oblique arrangement of the capitulum, which slopes downwards 

 from the carina towards the scutum. Darwin also refers to this : 

 " There is one more scale under the second latus than under the first 

 [or middle] latus, and one more under this than under the scutum; 

 hence the summit of the peduncle is obliquely truncated, being lowest 

 at the rostral end. In this respect there is some resemblance to the 

 genus Lithotryay 



Growth. — Under the subject of growth Darwin says (p. 84) : " New 

 scales for the peduncle are formed round its upper edge at the bases of 

 the valves of the capitulum, the chief growth of which is downwards : 

 hence we here have, as in other pedunculated Cirripedia, a principal 

 line of growth round the summit of the peduncle. It can be seen 

 that a new scale is first formed under the second latus, at the carinal 

 end of the peduncle, and this agrees with the fact that there is one 

 more scale in this row than in that next to it, and one more in 

 the latter than in the row under the scutum. I may mention, as 

 in conformity with this fact, that in the development of the young of 

 Scalpellum vulgare from the larval condition the calcareous scales on 

 the peduncle first appear under the carina." 



In Darwin's description of Loricula pulchella (op. cit., p. 81) he 

 describes the peduncle as having '■'■ten rows of smooth calcareous 

 scales, five rows upon the iipper and five rows on the under surface 

 of the peduncle, of which the six lateral rows are much elongated 

 transversely, and the four end rows nari'ow ; and that along the 

 rostral and carinal margins of the peduncle there is a straight medial 

 suture, with the scales not intersecting each other." 



Having carefully removed the Chalk from beneath one of Mr. Dibley's 

 specimens (now in the British Museum, No. I. 9130), I find that the 

 three principal rows (Fig. 1, cl, ml, and si) of much elongated calcareous 

 scales are absent, and I therefore venture to suggest that they were 

 not developed upon the underside of the peduncle, which was attached 

 to the shell of the Ammonite along the margins (Fig. 2, sc and ss)j 



DECADE T. VOL. V. NO. XI. 32 



