TBOCHOSPHEEE. 325 



the caudal cirri were absent (had fallen off), and a distinct papilla occupied the centre 

 of the caudal region. 



When fourteen feet are present a great advance has been made in regard to the 

 head, cirri, and feet. The head shows a blunt peak on each side, and the median 

 tentacle is proportionally large and long, while the palpi have not yet attained full 

 development, though they show the rows of minute papillae. Two large black eyes are 

 situated posteriorly, and two occur on the mid-lateral region, and are w 7 ell seen from the 

 dorsum. A considerable interval occurs betw T een the eyes of each side. All the cirri 

 have large clavate cilia. The posterior scales show large clavate papillae with palpocils 

 at the tip. The bristles at this stage are long, but they do not show distinctive 

 characters, though the attenuate condition of some of the dorsal suggests an approach to 

 Gattyana (Nychia). The specific identity of those captured in the tow-nets could not, 

 of course, be absolutely determined. 



A different trochophore appears in the nets in June, characterised amongst other 

 things by its black and brown pigment-belts at the ciliated ring, the former tint 

 being in front of the latter (Plate XXVI a, fig. 15). This form closely approaches 

 Dr. Hacker's species (Taf. iii, fig. 2) from Naples, though certain points of difference 

 are present. 



In this species the tips of the bristles seem to be less elongated, and the pre-oral 

 lobe is curiously marbled with black pigment. When scales form, the body is marked 

 in a somewhat tessellated manner, with transverse bars of reddish-brown pigment. At 

 this stage also the anterior end (ventrally) has two rounded, pigmented, lateral regions, 

 with a patch of black in the centre. A little later the black pigment bounds a median 

 central region in front, and there are six eye-spots, two large rounded eyes on each side, 

 and a black crescentic eye to the outer side of the anterior. 



The body is shorter, the feet more closely arranged, and the scales more persistent. 

 The latter have traces of low papillae on their outer edge, and the surface is roughly 

 areolated, probably from papillae, as might occur in the young of L. squamatus. When 

 the bristles are viewed from behind the spikes are alternate. The tips are much shorter 

 than in the previous form, and the shafts stouter. Large diatoms often occur in the 

 intestine. 



In the stage (Plate XXVI A, fig. 18) with the developing palpi the head is rounded 

 in front, and there are often three or four additional eye-spots besides the four normal. 

 The single spine of the first foot is prominent, and also two curved bristles. A band of 

 black pigment bounds the anterior border of the snout. 



There are eight feet, the dorsal bristles of which present very fine serrations, and 

 thus differ wholly from the previous forms. The ventral bristles have short tips with 

 rather closely arranged spinous rows. The caudal end terminates in a pointed pygidium 

 without cirri. In the early stages the bristles of the first foot are largely developed in 

 proportion, and must be especially useful in protecting the head. The cirri in this form 

 present a somewhat ovoid outline. 



As soon as the palpi have developed (Plate XXVI A, fig. 19) the head shows a deep 

 notch in the centre, the two large black eyes on each side being situated far back, the 



