44 



EEV. T. E. E. STEBBING— BISCAYAJST PLAJS^KTON 



Lepas anserifera, Linn. The sturdy, sliglitly hirsute horns, so distinctive of this larva, 

 project from near the front and the ventral margin. In dorsal view, as shown in the 

 diagram (fig. 4), they stand out like a pair of ears at right angles to the carapace. The 

 length of the shell is three and a half times its greatest width or thickness, as measured a 

 little to the rear of the horns, but not quite three times such width if measured along a line 

 including the horns. The dorsal margins diverge only a little in front, but for about a 

 seventh of the total length distally. In the middle of the length, but near tbe ventral 

 margins, therovind radiated scars of the adductor muscle can, with proper focussing, be 

 seen through the honeycomb markings of the valves. The appearance of the limbs and 

 small pleon is indicated in the adjoining figure (fig. 5). 



Fig. 4. 



As it were plastered against the inside of the valves below the eyes are the long glands 

 described by Glaus as shell-glands, agreeing in structure with that which he figures for the 

 (7{(pm-larva of Lepas australis [loc. cit. pi. 16. fig. 2, SD.). In the present form they are 

 rather more sinuous in shape. The antennae here represented (fig. 6), allowing for the fact 

 that they are still free, agree very nearly with Darwin's figure [loc. cit. pi. 30. fig. 8) of tbe 

 antennae in the attached Cypris of Lepas australis. The terminal joint, as shown more 

 highly magnified in fig. 7, has three short and two long setse, and, in addition, a narrow, 

 excessively transparent ribbon, answering to that which Darwin discusses {loc. cit. p. 118), 

 and believes " to be a tube of cement-tissue, which thus, sometimes even before the pupa 

 is attached, independently grows outwards." 



So far as I can discover, none of the authors who have examined this larval form have 

 supplied a figure of its external appearance, which is sufiiciently singular to have a good 

 claim to such a compliment. 



The place of capture was Station 32 a, between 50 fathoms and the surface. 



The figures of the carapace in lateral and dorsal view were drawn with the help of a 

 1-inch objective, those of the antenna and limbs with |-inch, and the distal part of the 

 antenna with a 5-inch. 



