251 Part III. — Twenty-second Annual Report 



moderately elongated, while the other two are short; the outer branches, 

 on the other hand, are provided with one terminal spine which is 

 moderately stout (fig. 9). 



The second pair appear to be more slender than the first, and the inner 

 branches are only one-jointed and bear a single moderately long apical 

 spine; the outer branches, which are two-jointed, are only armed with a 

 very short spine at the apex (fig. 10). 



The abdomen is very small and provided with two furcal joints which 

 bear a few minute setae. 



The Amphipod on which the parasite was observed occurred in a 

 surface tow-net gathering collected in Aberdeen Bay on October 16, 1903. 

 The parasite agrees very closely with the description and drawings of 

 S. egregius, Hansen, as given in that author's Monograph of the 

 Choniostomatidae referred to above, and therefore, though the Amphipod 

 on which it was found (Metopa borealis, G. 0. Sars) is a different species 

 from that mentioned by Dr. Hansen as the host S. egregius, I am 

 satisfied that the parasite I have described belongs to that species. 



The Amphipod on which Dr. Hansen obtained his specimens of 

 S. egregius belonged to Metopa bruzelii (Goes.). 



Sphceronella paradoxa, H. J. Hansen. PI. xv., fig. 17-19. 



1897. Sphceronella paradoxa, Hansen, The Choniostomatidse, 

 p. 118, pi. iii., fig. 4 a-1; pi. iv., fig. 1 a-h. 



The female of this Sphceronella represented by the drawing (figs. 16 

 and 17) is smaller than those described by Dr. Hansen, being only *57 mm., 

 whereas the smallest of the specimens mentioned by that author was 

 •71 mm. But with the exception of the difference in size the specimen 

 recorded here agrees very well with the species to which it is referred. 

 The specimen w T as found in the marsupium of Bathyporeia pelagica 

 (Bate). The figure representing a side view of the parasite shows the 

 posterior thread-like attachment considerably twisted upon itself and 

 terminating in a sucker disc ; the only other appendages visible are at 

 the anterior end, and comprise a pair of antennules and a pair of powerful 

 maxillipeds. 



Six specimens of Bathyporeia were found to be infested with 

 Sphceronella, and all the parasites observed appeared to be adult females. 

 The body of the female, represented by the drawings, is seen to be nearly 

 globular, particularly when viewed from above. 



The antennules are three-jointed, the end joint being the longest one 

 and the penultimate joint the smallest ; they are each provided with a 

 few setae (fig. 18). 



The maxillipeds (fig. 19) appear also to be three-jointed ; the first 

 joint is very large, but the other two are smaller ; the third is armed 

 with a moderately stout terminal claw, and as the articulation between 

 the first and second joints forms a hinge, the last two joints, together 

 with the terminal claw, can be folded upon the first, and this allows the 

 maxillipeds to be used as powerful grasping organs. 



No males were observed. 



Habitat. — In the marsupium of Bathyporeia pelagica (Spence Bate), 

 collected off Lossiemouth, Moray Firth, December 29, 1903. 



Sphceronella minuta, T. Scott, sp. n. PI. xv., fig. 11-15. 



An adult Sphceronella was obtained in the marsupium of a specimen 

 of Perioculodes longimanus (Spence Bate) from the Dornoch Firth, 

 collected by the bottom tow-net on December 28, 1903. Dorsal and side 

 views of the specimen are represented by fig. 12, 11. The length of the 

 specimen is *48 mm. (about ^ of an inch). 



