FAUNA OF THE OUTER WESTERN AREA OF THE CHANNEL. 315 



Position 33, in which there is a small raised osculum and the texture 

 is rather more compact., the specimens have all the same meagre 

 straggling habit of growth, with loose attachment to their base. The 

 skeleton has a more or less regular arrangement of compact multi- 

 spicular lines following a sinuous course from base to surface, with 

 spicules connecting these largely at right angles in such a way as often 

 to enclose with the main lines a series of rough rectangles, in the verti- 

 cal section. The spicular dimensions are very variable. The larger 

 main skeleton styli average about 180-200 ix in length, by 6-7 yu in 

 width. In the specimen from Position 36, the average width is lower 

 — about 5 /x. There is no clear line of separation between these and 

 the secondary styli, averaging about the same length and half the 

 width. Very slender, irregularly disposed, hair-like styli of 120 to 

 150 yu by 1 /y., or less than 1 /x, and isochelae averaging 18 to 20 fx 

 in length, are both usually very numerous. In the specimen from 

 Position 49 both are comparatively scarce. Except in this last-named 

 example abnormalities are frequent, in the form of medial bulb-like 

 swellings in the spicules. Sometimes these occur more especially in 

 the intermediate-sized styli ; often rather more so in those of the main 

 skeleton. The tendency is very pronounced in the specimen from 

 Position 38, in which a considerable proportion of the larger styli 

 show this abnormality, and occasionally two such swellings appear in 

 the shaft. In this specimen a large oxeote spicule occurs in one 

 section, with the same swelling in the centre. 



Esperiopsis sp. 



At Position 5, one specimen, forming large nodulous growths, almost 

 entirely covering a large specimen of Inachus dorsettensis ; with 

 two large oscula, 5 mm. in diameter, raised on prominences, 

 and numerous small ones, 1 to 2 mm. in diameter, scattered 

 over the surface. 

 Depth, 42 fath. 



While very distinct in its external form and more compact texture 

 from the preceding species, the internal structure and spiculation of 

 this specimen differ little from it. The main lines of the skeleton 

 have nearly the same arrangement. The chief difference lies in 

 the dimensions of the spicules, and this is not very considerable. 

 The larger styli average about 150 /x by 7 yci ; intermediate styli, 

 150 /i by 2-3 jm ; hair-like styli, occasionally centrotylote, 100- 

 150 /jt in length, not very numerous ; isochelae of the same form and 

 size as in the last species, very scarce. But for Bowerbank's remark 

 concerning the great irregularity of the main skeleton of imitata, which 



