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 sete (fig. 29). 
The antenne 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 maxille, 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). 
ae 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. 
Tt 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 Botryllophilus (?) ruber; not very common. 
The Botryllus was dredged in the Moray Firth in 1896. 
Remarks.—This species, if not a true Hnteropsis, 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 H’nterapsis, the 
one now described may have to be removed to some other genus or a new 
one instituted for its reception. 
Botryllophilus (2) ruber, Hesse. (Pl. XVIL., figs. 15-27.) 
1864. Botryllophilus ruber, Hesse, Ann. Sci. Nat., Zool. (5), t.1., 
Pl. XII., figs. 1-7. 
1900. Botryllophilus (%) ruber, T. Scott, 18th Ann. Rept. Fishery 
Board for Scot., Part IIL, p. 388. 
In my paper “ Notes on some gatherings of Crustacea,” published in 
Paper III. of the Eighteenth Annual Report, I recorded the occurrence of a 
Botryllophilus, in the Clyde and the Moray Firth, under the name of Bot- 
ryllophilus (1) 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 
