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Part III. — Fifteenth Annual Report 



Jonesiella spinulosa (Brady and Robertson). — Near Largabruach, 

 Upper Loch Fyne, in dredged material (G.). Jonesiella fusiformis, which 

 in some localities appears to be a more common species than the one 

 recorded here, has not yet been observed in any of the collections made 

 by the 1 Garland ' in the Clyde. 



Delavalia robusta (Brady and Robertson). — Near Largabruach, Upper 

 Loch Fyne, in dredged material ; not very rare (G.). 



Delavalia mimica, sp. n. (PI. I. figs. 1-9.). 



Description of the Female. — Length, *65 mm. (ygth of an inch). Body 

 moderately stout, and somewhat like Delavalia refexa in general appear- 

 ance. Antennules eight-jointed, the penultimate joint is smaller than 

 any of the others, while the last is rather more elongate than either of the 

 preceding three or four joints (fig. 2). The antennae and mouth organs 

 are somewhat similar to those of D. reflexa ; the principal seta of the end 

 joint of the mandible-palp is moderately stout and curved, and of con- 

 siderable length (fig. 3). The inner branches of the first pair of swim- 

 ming feet are three-jointed, the first joint is rather longer than the entire 

 length of the three-jointed outer branches, but the second and third are 

 short, and together scarcely equal to half the length of the first joint 

 (fig. 5). The second, third, and fourth pairs do not differ much from 

 those of other species of Delavalia (fig. 6 shows the fourth pair). The fifth 

 pair, which have a general resemblance to those of other species of Dela- 

 valia^ differ in the following points : the armature of the basal joint con- 

 sists of three moderately short and rather stout spines, situated on the 

 apex of the slightly produced inner portion, in addition to two spiniform 

 setae, one of which is exterior and the other interior to the spines; the 

 innermost of the three spines, which is also the largest, bears two minute 

 marginal hairs near its extremity — one on either side. The secondary joint 

 is lamelliform, moderately broad, and subcylindrical. The margins, which, 

 in the middle of the joint are somewhat parallel, converge towards both 

 ends, and the distal end, which for this reason assumes a triangular form, 

 is provided with five setae and a short stout spine ; this spine is situated at 

 the beginning of the exterior distal slope, while the five setae are arranged, 

 two on each sloping distal margin, and one at the apex, as shown in the 

 drawing (fig. 7). 



Description of the Male. — The male differs little from the female except 

 in the form and armature of the fifth pair of feet. The basal joint of the 

 fifth pair bears interiorly a single, and somewhat peculiar, stout, and mode- 

 rately large spine, and a small spiniform seta ; the secondary joint is 

 small, subovate, and armed with three spines on the oblique distal end of 

 the exterior margin ; there is also a seta at the apex and another on the 

 inner margin, as shown by the drawing (fig. 8). The second pair in the 

 male were not modified, as is sometimes the case, but resembled those of 

 the female. 



Habitat. — Loch Gair, Upper Loch Fyne. It has also been obtained in 

 other parts of the Clyde district, and in the Firth of Forth at Granton. 



Remarks. — This species differs very markedly from any other Delavalia 

 known to me in the structure of the first pair of swimming feet ; this pair 

 are not very unlike those of some species of Dactylopus or Ameira ; but 

 as the structure of the mandibles and of the fifth pair of feet is that of 



