o 



of the Fishery Board for Scotland. 46 



Leptopontia curvicauda, T. Scott (sp, n.). PI. XXII., figs. 26-35. 



Description of the Female. — Length '6mm. (about -^ of an inch). 

 Body slender, cylindrical ; cephalo-thoracic segment moderately short, 

 scarcely three times the length of the next one ; rostrum short (fig. 

 26). 



The antennules are slender and longer than the cephalo-thoracic 

 segment, seven-jointed, the first joint is longer than any of the others, the 

 second and third are sub-equal, the fourth, fifth, and sixth joints are each 

 about half the length of the third, while the end joint is about twice the 

 length of the one next to it (fig. 27). The formula shows approximately 

 the proportional lengths of the different joints : — 



Proportional lengths of the joints, - 28 • 18 • 17 * 8 • 7 * 7 • 14 

 Numbers of the joints, - - - l'2'S'4: , 5'Q'7 



Antennae slender, consisting of two elongated joints ; the secondary 

 branches are represented by a single minute hair (fig. 28). 



Mandibles slender and elongated, the biting end is obliquely 

 truncated and armed with a number of small teeth ; the mandible-palp 

 is also elongated, and one branched, the basal joint is moderately stout, 

 and about twice the length of the single-jointed branch, and is furnished 

 with a few small setae (fig. 29). 



The posterior foot-jaws (fig. 30) are not unlike those of Tetragoniceps 

 incertus, T. Scott. The inner branches of the first pair of thoracic feet are 

 slender, elongated, and two-jointed, the end joint being only about one-third 

 the length of the other; the outer branches, which are three-jointed, are 

 scarcely half the length of the inner branches (fig. 31). In the second, 

 third, and fourth pairs the outer branches are long and slender, and three- 

 jointed ; the joints of the outer branches of the second pair are sub-equal 

 in length, but in the outer branches of the third and fourth pairs the first 

 and second joints are sab-equal and rather longer than the end joints. 

 The inner branches of the same three pairs are short and two-jointed ; 

 in the second pair the inner branches are rather longer than the first 

 joint of the outer branches ; but in the third and fourth pairs the inner 

 branches are shorter than the first joint of the outer branches, as shown 

 by the drawing (figs. 32, 33). 



In the fifth pair the basal joints are moderately large and foliaceous, 

 the inner produced part is broadly rounded, and bears three apical setae, 

 and the secondary joints, which are very small, also carry three setae (fig. 34). 



The last abdominal segment is armed on the median dorsal aspect 

 with a backward-pointing tooth as shown in figures 26 and 35. 



The caudal furca, which are nearly as long as the last abdominal 

 segment, become gradually attenuated towards the distal extremity ; and 

 in all the specimens that have been obtained the furca are distinctly 

 recurved as shown in the habitus drawing (fig. 1). 



Habitat. — Dredged in the Firth of Forth at Station VI. (off St. Monans) 

 on July 8th, 1901 ; not very common. 



Remarks. — Odd specimens of this species have been observed from 

 time to time for a considerable while past, but the first specimens were 

 put aside as being probably immature forms of some species already 

 described. I am now, however, convinced that they are distinct 

 Leptopontia in some respects resembles both Mesochra, Boeck, and 

 Tetragoniceps, G. S. Brady, in its structural details, but in the absence 

 of a secondary branch to the antennae, in the elongate and slender form of 



