512 ON THE FAUNA AND r.OTTOM-DEPOSITS NEAK THE 30-FM. LINE 



the Eddystone only occasional pieces of these polyzoa are met with, 

 whilst it has never been taken on the shell gravel grounds. (Chart XVI.) 



Scrupocellaria scruposa. After the two species of Cellaria this is the 

 most abundant branched polyzoan. It is plentiful both on the fine sand 

 grounds and on the gravels in the neighbourhood of the Eddystone. It 

 is generally attached to the tubes of polychaetes {e.g., Thelcjms, Chae- 

 topterus variopcdatus) or to the base of Cellaria. It is rarely met with 

 on the shell gravel grounds and on the Prawle Stony Ground. 



Biccllaria 'ciliata is not unfrequently met with attached to hydroids 

 of various kinds. The most common species of Bugula is B. avicularia, 

 and B. fiahellata is also occasionally taken. Cdlcpora avicularis and 

 Cellcpora ramulosa are abundant on the fine sand grounds attached to 

 hydroids. Incrusting Polyzoa are plentiful on all grounds where mollusc 

 shells are numerous (see Table VI.). 



TUNICATA. 



Nomenclature: — Herdman, " Ee vised Classification of the Tunicata," 

 Journ. Linn. Soc., XXIII., 1891. 



In the identification of the Tunicata I have received much help 

 from my colleague, Mr. W. Garstaug. 



Molgula oculata. Specimens of this species were only occasionally 

 taken, covered in each case with broken shell gravel. They occurred on 

 the clean broken shell of Ground XVI. immediately to the westward of 

 the Eddystone rocks, and on the coarse gravel of Ground XL to the 

 north-west of the Eddystone. The species is one which is usually 

 taken only on coarse ground. 



Molgula simplex. Specimens which we have identified as M. siinplex 

 occurred somewhat frequently on Chactopterus tubes, though they were 

 not recorded in many of the hauls, owing to their only having been 

 identified at a somewhat late stage in the investigation. The specimens 

 were usually 5 or 6 mm. in diameter. The species probably occurs on 

 all the Chaeto2)terus grounds. 



Forbesella tesselata. One specimen only on the fine gravel ground 

 XV. 



Siyelo'psis grossularia. The small squat variety of this species was not 

 unfrequently met with on shells, especially Pecten shells, on the gravels 

 to the westward of the Eddystone and on the Bolt Head Shell Gravel. 



Polycarpa varians, Heller = (P. pomaria, Sav.). This species is very 

 much restricted to one area, west and south-west of the Eddystone, 

 where, however, it is abundant, and forms a striking and characteristic 

 feature of the fauna. It is very abundant on Grounds IX. and XIV., 

 on li()th of which the bottom- deposit is gravel, and also on those hauls 



