NO. 1531. ADDITIONAL NOTES ON THE A RGULIDyE— WILSON. 415 



water. Furthermore we are certain that in the present instance the 

 period of development is normal, for these eggs were kept at the same 

 temperature as the ocean water in which the}^ would naturally have 

 been laid. The following- is a description of the larvre obtained: 



Carapace heart shaped, a little wider than long; not much narrowed 

 anteriorl}^; its entire margin fringed with delicate hairs, amongst the 

 anterior two-thirds of which are scattered longer tactile hairs. Pos- 

 terior sinus very shallow, the lateral lobes wide and well rounded. 

 The large eyes are placed well forward and are widely separated. 

 The cephalic area is clearly differentiated from the lateral areas at the 

 sides and from the thoracic area posteriorly, and considerable move- 

 ment is possible between these areas. The skin glands are not as 

 large as those of the 7negalo/js larva?, but there is a row of ten or 

 twelve of medium size on either side parallel with the margin of the 

 posterior portion of the lateral lobes. 



The first antenna?, like those in the megalops larva, have assumed 

 nearly their permanent form. The basal joint is armed with a broad 

 and blunt posterior spine, and the usual sickle-shaped claw on its 

 lateral margin. The terminal joints are comparatively stout and do 

 not project much beyond the claw of the basal joint. The second 

 antenna? are also of the adult form, slender, four jointed, and termi- 

 nating in a small claw. 



On the ventral surface, inside the base of these antenna^ and imme 

 diately behind the large posterior spine of the first pair on either side, 

 is another spine of the same size and shape. 



The first maxillipeds are very large and stout and three jointed, 

 the basal joint much swollen and bearing on its ventral surface near 

 the distal end two large flat spines. 



The second joint is much shorter and narrower, though still stout; 

 the terminal claw is sickle-shaped, with the usual three barbs on its 

 inner margin at the tip. The posterior maxillipeds are large and 

 stout also, the basal joint with a pair of strong spines on its posterior 

 border, the terminal joint with two stout and movable claws and a 

 straight, rounded knob. 



The ventral surfaces of the three middle joints are well armed with 

 flattened laminae, one edge of which is raised and cut into long and 

 sharp teeth. Between the bases of these maxillipeds, on either side 

 of the mid line, is a slender and sharp sjiine. 



The mouth tube is short and wide, with a framework quite similar 

 to that in megalops. The mandibles, however, are not toothed along 

 their inner border, and there are no labial palps visilfle. The retrac- 

 tile proboscis is comparatively large and stout. Free thorax seg- 

 ments wide and quite long, leaving considerable space between the 

 posterior border of the carapace and the abdomen. Each segment 

 carries a pair of swimming legs fully developed and of practically the 



