242 REPORT OF COMMISSIONER OF FISH AND FISHERIES. = [536] 
legs are subequal with the others and have styliform dactyli. The 
ischial and meral segments of the external maxillipeds are short and 
broad. 
Another megalops, of which several specimens were taken in the 
towing-net, in Vineyard Sound, August 5, has a remarkable, elongated 
and tuberculated carapax. The carapax, including the rostrum, is 
1.3" long and 0.84" broad, is armed above with several large 
tubercles, and the posterior marginis arcuate and armed with a median 
tubercular prominence. The front is somewhat excavated above and 
expanded each side in front of the eyes, the anterior margin being trans- 
verse, as seen from above, with a short and spiniform rostrum curved 
obliquely downward. The chelipeds have slender hands and the am- 
bulatory legs are long and slender, the posterior pair being subequal 
with the others, and all having the dactyli styliform. The abdominal 
legs are very long. 
Several other forms of zoéa and megalops were taken in Vineyard 
Sound and vicinity, but, as they were not traced to the adult forms and 
were none of them very abundant, they are not here described. 
Squilla enpusa passes through a remarkable metamorphosis, but none 
of the earliest stages were observed. Specimens in one of the later 
larval stages (Plate VIII, fig. 36) were taken at the surface in Vine- 
yard Sound, August 11. These are nearly 6'" long. The carapax is 
proportionally much larger than in the adult, covering completely the 
whole cephalothorax, has a long slender rostrum projecting far in front 
of the eyes, and the lateral angles projecting backward in two slender 
processes as long as the rostrum. There is also on each side, just behind 
the eye, a small tooth on the margin of the carapax, and another similar 
one on the posterior margin just beneath each of the posterior processes. 
The eyes are very large and almost spherical. The antennulz are short, 
projecting scarcely beyond the eyes, and biramous, one of the flagella 
being short and unsegmented, the other longer and composed of three 
segments. The antenne are still without flagella, and the scale is 
quite small. The first pair of legs (the appendages corresponding to 
the first pair of maxillipeds in the Macroura, &c.) are well developed, 
long, and slender, like those of the adult. The great claws are propor- 
tionally larger than in the adult, and have very much the same structure. 
Of the six succeeding pairs of cephalothoracic legs, only the three ante- 
rior, subcheliform ones are as yet developed, and these are quite small, 
those of the third pair being smaller than the others, and projecting but 
Slightly beyond the carapax; the three posterior, styliform legs are en- 
tirely wanting, or represented only by slight sack-like protuberances. 
The abdomen is not quite as long as the cephalothorax, including the ros- 
trum and posterior processes, and the five anterior segments are subequal 
in length, smoothly rounded above, and furnished with well developed 
Swimming-legs, much like those of many macrouranas. The sixth seg- 
ment is much shorter than the others, and has rudimentary appendages 
