of the Fishery Board for Scotland. 252 



The antennules appear to be three-jointed ; the first joint is nearly 

 twice as long as the second, while the third is equal to rather more than 

 the entire length of the first and second (fig. 13). 



The first maxillipeds are very small, and consist of a single stout joint 

 armed with a moderately strong terminal claw (rig. 14). 



The second maxillipeds are rather more slender and elongated than the 

 other pair ; the basal joint is twice as long as broad ; the next two are 

 small and narrow, and appear to be hinged to the basal joint ; the 

 terminal claw, which is moderately stout, is slightly curved (fig. 15). 



Dr. Hansen states that he obtained female Sphceronellas in the 

 marsupiums of three specimens of Perioculodes lonyimanus from 

 Denmark, and that they appeared to be identical with S. paradoxa, the 

 only appreciable difference being their smaller size. Dr. Hansen's exten- 

 sive knowledge of this curious and difficult group of Crustacea precludes 

 any doubt concerning the accuracy of the identification of these specimens. 

 I am therefore inclined to regard the Sphceronella found on the Perioculodes 

 from the Dornoch Firth as a somewhat different form from those he 

 observed, and have described it provisionally under a distinct specific name. 



This Sphceronella from the Dornoch Firth Perioculodes appears to 

 differ not only in size and shape from S. paradoxa, but also in the size 

 and proportional lengths of the joints of the antennules and in the size 

 and structure of the second maxillipeds. 



Sphceronella callisomce, T. Scott, sp. n. PI. xv., fig. 20-27. 



The Sphceronella I record under this name was obtained on a specimen 

 of Callisoma crenata (Spence Bate) collected at the mouth of the Firth 

 of Clyde on February 7, 1899. The parasite is an adult female and 

 measured '86 mm. in length (= -^ of an inch). The body seen from 

 above is nearly globular; and the cephalon is seen projecting somewhat 

 beyond the anterior aspect in the form of a moderately conspicuous 

 tubercle (fig. 21). Seen from the side the body is broadly oblong, with 

 both the anterior and posterior ends boldly convex. The anterior portion 

 of the body appears to be thickly beset with minute hairs (fig. 20 and 21). 



The antennules are three-jointed ; the middle joint is very short, but 

 the other two are moderately elongated (fig. 22). 



The antennas are very small and uniarticulate, and are each furnished 

 with a single terminal seta about as long as the antennal joint (fig. 23). 



The mandibles are slender, elongated, and sub-cylindrical (fig. 24). 



The maxilla? are stout, and are each apparently composed of a single 

 piece, and armed with two moderately stout terminal seta?, while a third 

 seta springs from a minute lateral process, as shown in the drawing (fig. 25). 



The first and second maxillipeds have each of them moderately stout 

 basal joints, and they are each provided with strong terminal claws 

 (fig. 26, 27). 



The ventral filament, which is furnished with a terminal sucker-like 

 disc, is long and slender, and twisted upon itself as shown in fig 20. 



This Sphceronella does not agree with any described species known to 

 me. 



Sphceronella cluthce, T. Scott, sp. n. PI. xv., fig. 28-30. 



A single adult female of this Sphceronella was obtained in the 

 marsupium of a specimen of Harpinia pectinata, G. 0. Sars,* found in a 

 tow-net gathering collected in moderately deep water at the mouth of the 

 Clyde estuary, and nearly midway between Ailsa Craig and Sanda 

 Island ; this tow-net gathering was collected on November 14, 1899. 



* Some remarks on the distribution of this Harpinia will be found among the Notes 

 on Amphipoda at page 256. 



