G40 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 

 Family PALiEMONiDyis. 



PAL^MON OhIONIS, SJJ. 710V. 



Carapax SQiootb, stout, and considerably swollen ; tlie antennal and 

 hepatic spines acute and of nearly equal size. Rostrum sliort, reaching 

 scarcely to the tips of the antennal scales; its height in the middle about 

 a third of the length, with a ver^' high and arched lamellar crest 

 above, not extending back of the middle of the carapax, and armed 

 with ten to twelve slender teeth, of which the two or three posterior are 

 back of the bases of the ocular peduncles, and more separated from each 

 other than the anterior ones; inferior edge arcuate and armed with two 

 or three teeth ; the terminal, third or fourth unarmed and directed 

 slightl3' upward to the acute tip. Antennal scale- about two-fifths as 

 broad as long; the edges nearly parallel ; the tip broad, subtruncate. 



First pair of legs smooth and slender, the carpus, in large specimens, 

 reaching beyond the tips of the antennal scales ; merusand carpus sub- 

 equal in length ; hand very slender, about half as long as the carpus ; 

 fingers not quite half as long as the whole hand, cylindrical, armed 

 with a few fascicles of seta?. Second pair of legs slender, either equal 

 or somewhat unequal on the two sides; the ischium, merus, and carpus 

 subequal in length ; the carpus, in full-grown specimens, reaching much 

 beyond the tips of the antennal scales, cylindrical, tapering proximally, 

 and armed with scattering spinules, or short hairs ; hand considerably 

 longer than the carpus, slender; the basal portion of the propodus 

 slightly swollen, nearly cylindrical, and armed with minute spinules ; 

 the fingers much shorter than the basal portion of the propodus, slender, 

 not gaping, nearly straight, and armed with a few fascicles of short 

 setiform hairs. Succeeding legs increasing slightly in length posterior- 

 ly ; all of them with short, strongly-curved dactyli, and reaching slightly 

 beyond the tips of the antennal scales. 



Fourth and fifth segments of the abdomen produced at the posterior 

 lateral angle, which is rounded in the fourth segment and acutely angu- 

 lar in the fifth. Sixth segment only a little longer than the fifth. Tel- 

 son narrow, considerably shorter than the inner lamellie of the append- 

 ages of the sixth segment, tapering regularly to the acutely triangular 

 tip, which is armed each side with two slender spines and numerous 

 long plumose seta?; the dorsal surface armed with two pairs of short 

 Spines. 



Two specimens give the following measurements : 



Male. Fomale. 



mm. mm. 



Leugtli from tip of rostrum to extremity of telson 51 . 80. 



Length of carapax from orbit to middle of posterior margin 12. 22. 



Breadth of carapax 7. 8 14. 



Length of rostrum from its tip to base of ocuhir peduncles 8. 2 13. 5 



Length of basal scale of antenna 8. 4 32. ^ 



Length of iirst pair of legs 16. 8. 3 



Length of ujerus in first pair of legs 4. 2 10. 



