NEW AND RARE SPECIES OF COPEPODA FROM SCOTLAND 31 



thirds of their entire width across the broadest part ; the 

 secondary branches are very small, obscurely triangular in out- 

 line, and furnished each with three small setae on the outer edge 

 (Fig. i 2). The caudal stylets are in the form of elongate- 

 ovate lamellae ; in length they are equal to both the last two 

 abdominal segments together, and their breadth is about 

 equal to two-thirds of their length ; they are also each fur- 

 nished with four terminal setae, the principal seta being about 

 twice the length of the stylets, but the others are very small. 

 Ovisac small, containing a number of moderately large ova. 



Male. The male is similar to the female, except in the 

 following particulars : The anterior antennae are each six- 

 jointed ; the last four joints are modified and hinged, and 

 form powerful grasping organs. The basal joints of the 

 fifth pair of thoracic feet are coalescent, as in the female, but 

 are much shorter, being only about half the length ; the 

 sixth pair of appendages are foliaceous, broadly subtriangular 

 in outline, and not coalescent (Fig. I 3). 



Habitat. In pools near low water on the shore of the 

 Firth of Forth, at Musselburgh ; rather rare. 



Remarks. This species is at once distinguished from 

 any others of the same genus by the large, lamelliform 

 caudal stylets, and by the form of the fifth pair of thoracic 

 feet, as also by the structure of the anterior antennae. We 

 have much pleasure in giving to this species the name of our 

 kind friend Mr. David Robertson of Millport, the veteran 

 Scottish Naturalist, who was one of the first to introduce us 

 to that most interesting study the study of the Micro- 

 crustacea. 



LEPTOPSYLLUS MINOR, sp. nov. (Plate II. Figs. 15-22). 



Description. Female. Length, -46 mm. (-% of an inch). 

 Body elongate, very slender. Anterior antennae short, 

 moderately stout, seven-jointed, somewhat similar in structure 

 to those of Leptopsyllus robertsoni. The proportional lengths of 

 the joints are shown by the formula- 

 Proportional length of joints 20 14 n 7 5 9 10 

 Number of the joints i 2 3 4 5 6 7 ' 



