242 Part III. — Nineteenth Annual Report 



and the cephalic appendages are therefore somewhat crowded together near 

 the anterior end and on the ventral aspect of the body. The thorax exhibits 

 a slightly articulated structure, but there is no apparent segmentation of 

 the abdomen, this part of the body is not differentiated from the thorax ; 

 the caudal appendages are very small (fig. 28). 



The antennules are very short and moderately stout; they taper 

 towards the distal end, and are each composed of three joints of nearly 

 equal length, and bear three short terminal spines, but are otherwise 

 unprovided with spines or setae (fig. 29). 



The antennae are simple, and are each composed of two dilated joints 

 and armed with a strong terminal claw ; there are no secondary branches 

 (fig. 30). 



The mandibles are of moderate length, and they each consist of a 

 stout and slightly curved claw-like appendage ; there does not appear to 

 be a mandible-palp (fig. 31). 



The maxillae, which are of a simple structure, appear to be two- jointed, 

 the basal joint is stout, but the end one consists of a somewhat narrow 

 and elongated plate, rounded and slightly crenulate at the extremity 

 (fig. 32). 



Only one pair of maxillipedes could be made out, and these are very 

 rudimentary ; they each consist of a slightly elevated and broadly rounded 

 prominence armed with a small apical spine (fig. 33). 



The thoracic feet comprise four pairs, they are very small but com- 

 paratively stout, and appear to be all more or less uniform in structure. 

 Each foot is composed of a single two-jointed branch, both joints are 

 somewhat dilated, but the end one is much smaller than the other, and is 

 armed with two short and apparently movable terminal spines (fig. 34). 

 The position of the first pair is somewhat abnormal, they are not in line 

 with the other three pairs, as is more or less usually the case with free- 

 living species, but are situated round towards the lateral aspect; this 

 position of the first pair does not appear to be accidental, but has been 

 observed in the other specimens examined. 



It will also be observed that the genital opening is situated on the 

 dorsal aspect of the abdominal part of the body (see fig. 28). 



Habitat. — In the branchial chambers of a compound Ascidian (Bot- 

 ryllus sp.), associated with Boiryllophilus (?) ruber ; not very common. 

 The Botryllus was dredged in the Moray Firth in 1896. 



Remarks. — This species, if not a true Enteropsis, is very closely allied 

 to that genus. The most important point of difference seems to be the 

 apparent absence of a mandible-palp. If the presence of this appendage 

 is clearly established in the other members of the species Enteropsis, the 

 one now described may have to be removed to some other genus or a new 

 one instituted for its reception. 



Botryllophilus (?) ruber, Hesse. (PI. XVIL, figs. 15-27.) 



1864. Botryllophilus ruber, Hesse, Ann. Sci. Nat., Zool. (5), t. i., 

 PI. XII., figs. 1-7. 



1900. Botryllophilus (?) ruber, T. Scott, 18th Ann. Kept. Fishery 

 Board for Scot., Part III., p. 388. 



In my paper "JSTotes on some gatherings of Crustacea," published in 

 Paper III. of the Eighteenth Annual Eeport, I recorded the occurrence of a 

 Botryllophilus, in the Clyde and the Moray Firth, under the name of Bot- 

 ryllophilus (?) ruber, Hesse, but only the females had at that time been 

 observed. In consequence of further research I am able to give a more 

 detailed description of the species than was done last year, and to include 



