67 



exceedingly powerful, representing the chief attaching organs of the animal. 

 The 4 anterior pairs of legs more or less reduced and; as least in female, 

 quite unsuitable for swimming. Last pair of legs in female transformed 

 as supports for the ovisacs. 



Remarks. This family is established to include 3 nearly allied genera, 

 to be treated of in the sequel, that of the earliest date being Botryllophilus 

 Hesse. The family agrees with the Ascidicolidce in the presence of free orisacs 

 in the female, but differs considerably in the structure of the several appen- 

 dages, the most prominent difference being the transfer of the affixing faculty 

 to the posterior maxillipeds. 



Gen. 12. Botryllophilus, Hesse, 1864. 



Generic Characters. Anterior division of body in female very sharply 

 marked of from the posterior and rather tumid, carrying at the end, on each 

 side, the transformed 5th pair of legs. Tail narrow cylindric in form, and 

 composed of 4 well defined segments. Anterior antennae with the number of 

 segments rather reduced. Posterior antennae with the middle joint very short, 

 terminal joint elongate and armed with strong spines. Mandibles with the 

 masticatory part considerably expanded, palp biramous with the inner ramus 

 largely developed, the outer very small. Maxillae with the exopodal lobe 

 obsolete. Anterior maxillipeds comparatively feeble in structure, and divided 

 inside into a number of digitiform lobes, each tipped with a single curved 

 spiniform seta. Posterior maxillipeds very powerfully developed, and pro- 

 nouncedly prehensile, terminating in a claw-like biarticulate digit. The 4 

 anterior pairs of legs (in female) with the rami short, uni- or biarticulate, the 

 outer one spiniferous, the inner setiferous. Last pair of legs in female forming 

 2 narrow setiferous lappets attached to the sides of the last trunkal segment 

 and extending backwards, encompassing between them the single or double 

 ovisac. The latter more or less globular in form. 



Remarks. The present genus was established as early as the year 1864 

 by Hesse, to include a peculiar Copepod (B. ruber) found by him within a 

 compound Ascidian (Botryllus). Subsequently 2 forms evidently referable to 

 the same genus were recorded, the one by Scott from the Scottish coast, the 

 other by Canu from the French coast. Scott identified, though with some doubt, 

 the form observed by him with Hesse's species, whereas. Canu regarded his 

 form as a new species and described it under the name of B. macropus. As 



