ON INDO-MALAYAN BARNACLES. 75 



t 



Of A. malaysiana two specimens were obtained — a very young individual and another, 

 probably adult, to the peduncle of which the former was fastened. In some respects this 

 species resembles A. lankesteri, Gruvel, 1 and its allies ; but it is distinguished from them 

 externally by the possession of a regular carinal crest and by other peculiarities. 



SCALPELLUM INERME, Sp. nOV. 



Description — 



Capitulum laterally compressed, almost quadrilateral, formed of stout, rather 

 brittle, feebly translucent, smooth membrane, to the inner surface of which 14 small, 

 thick, white, opaque plates are attached, being invisible externally except for the upper 

 part of the terga, carina and scuta and the free extremity of the carinal latus. The lines 

 of growth are well marked upon them. Carina bent on itself at an angle and differen- 

 tiated into a vertical and a horizontal limb, a prominent tooth which terminates in the 

 umbo occurring at their point of junction. Dorsal surface of horizontal limb convex ; 

 lateral surfaces rounded, low ; the former, as seen from above, expanding gradually from 

 point of junction and somewhat dilated at the free extremity. Vertical limb flat on 

 the dorsal surface except for a slight median ridge ; no distinct borders ; sides for the 

 most part almost vertical, deeply concave near junction of two limbs ; general form of 

 limb, as seen from behind, a narrow isosceles triangle, but with a wedge-shaped base. 

 Scuta also differentiated into two parts, the lower of which is subtriangular, with the lateral 

 margin feebly convex, the basal margin slightly concave and the occludent margin 

 almost straight ; the upper or tergal part narrow, elongated, rectangular ; these two parts 

 united by a narrow, depressed strip running down occludent margin of each ; umbo at 

 junction of two parts; the lower part deeply concave internally in contact with the 

 mantle. Terga j^ -shaped, the scutal border very deeply excavated; umbo at apex, near 

 upper margin of capitulum, widely separated from free extremity of carina. Upper Latus 

 very small, widely separated from other plates, rhomboidal, with five facets on its external 

 surface ; umbo near centre. Rostral Latus leaf-shaped, pointed at occludent extremity, 

 blunt towards inframedian latus, with a slightly curved ridge along its major axis. Infra med- 

 ian Latus small, subquadrangular, oblong ; the major axis cari no -scutal, with three facets 

 on external surface and a narrow depressed slip inferior to them. Carinal Latus crescen- 

 tic, protruding, with an additional flattened strip running along its middle third on the 

 carinal margin. Rostrum saddle- shaped, astride occludent surface of the capitulum, with 

 its apex penetrating the membrane nearly to the external surface ; part of each limb in- 

 ternal to rostral latus. 



Peduncle stout, cylindrical, flexed, of equal diameter throughout, about 1^ times as 

 long as capitulum, armed with 45 rings of regular, homogeneous, oval scales arranged in 

 such a way that they overlap at the ends round the circle, and covered with a thick 

 membrane plentifully set with short brownish hairs. (Possibly similar hairs would be found 

 on the capitular membrane of an individual which had not been occluded by another 

 organism). 



1 Trans. Linn, Soc, Zool. (2) VIII., p. 282. 



