9i 



unsuitable. The specimen consists of several groups of zooecia, each of which arises from an 

 isolated base completely surrounding the jointed tubular object which Busk mistook for the stem 

 of the Hippuraria. The base is of precisely the same nature as that described as a "continuous 

 crust" by Duerden (1893), in Triticella boeckii and other species. The zooecia show the gibbous 

 "dorsal" outline which is so characteristic of that species; and agree with it in the position and 

 general development of the curved chitinous thickening of the ectocyst described by Duerden as 

 the "frenaculum". The comparison of Busk's specimen of Hippuraria egertoni with undoubted 

 specimens of T. boeckii leads me, in fact, to the conclusion that the two forms are identical. 



The label of Busk's slide states that the specimens was "Attached to eye of Gonoplax 

 angulatus' . An examination of the supposed stem of the Polyzoon shows that it is a jointed 

 structure, bearing rings of minute spines at the joints. Mr Waters regarded it as a seaweed, 

 but it appears to me nearly certain that it is really a fragment of the flagellum of the antenna 

 of the Gonoplax. Dr W. T. Calman, whose opinion I asked, agrees with this conclusion. The 

 base of the antenna lies close to that of the eye in Gonoplax, as may readily be seen by 

 examining a specimen of the crab. When it is remembered that Busk mistook the antenna for 

 part of the Hippuraria, the statement that the Polyzoon was attached to the eye of the crab 

 becomes readily intelligible. 



In order to obtain further evidence with regard to the nature of Hippitraria I asked 

 Dr Calman to select specimens of Gonoplax which seemed likely to bear this interesting form. 

 He was kind enough to send me specimens, from the collection in the British Museum, on 

 several of which there was 110 difhculty in finding perfectly typical specimens of Triticella 

 boeckii. All the crabs are labelled Gonoplax rhomboides Linn., with which, as Dr Calman informs 

 me, G. angulata Fabr. is generally regarded as synonymous. The specimens on which T. boeckii 

 was found are as follows : — 



(1) 98.5.7.251 — 252. Bay of Biscay, "Porcupine", 1870, Coll. Norman ; on 5 specimens, attached 

 principally to the bases of the walking legs, particularly on the dorsal side, in the angles 

 between the legs and the carapace. 



(2) 1 9 1 1 . 11. 8. 34. Off Valentia, Ireland, "Porcupine", 1869, Stat. 6, 90 faths, Coll. Norman; 

 on 1 specimen. 



(3) 191 1. 1 1. 8. 3 1. Cadiz Harbour, Coll. Norman ; on 1 specimen. 



(4) 191 1. 11. 8. 35 — 38. Off Cape Sagres [Portugal], 45 faths, "Porcupine", 1S70, Coll. Norman; 

 on 1 specimen. 



(5) 1910. 2.4. 180 — 182. Same locality; on 1 specimen. 



(6) 96. 5. 195 — -198. Algoa Bay, H. A. Spencer; on 4 specimens, growing on the bases of the 

 legs and great chelae; also on the third maxillipedes, and on the edges of the abdomen. 



(7) Crab not determined [Gonoplax sp.), 16 miles N. E. of Bird Is [Algoa Bay], 40 faths, 

 F. Toppin 1905; on 1 specimen, growing on the bases of the walking legs; on the second 

 and third maxillipedes; on the "front", close to the antennae; in the orbits; on the back 

 of the carapace; and on the abdomen. 



The localities given for T. boeckii by Duerden (1893) are Berehaven, S. W. Ireland 



91 



