PARACRANGON AREOLATA. 129 



Paracrangon areolata Fax. 

 Plate XXXIV. 



Bull. Mus. Comp. Zool., XXIV. 200, 1893. 



Body robust, integument indurated, keeled and sculptured. Rostrum 

 long, acute, strongly upturned, laterally compressed, superior margin entire, 

 inferior margin armed with two spines, one long one near the base above 

 the eyes, and one small one near the tip. A prominent carina, continuous 

 with the rostrum, extends the length of the carapace in the median line ; it 

 is armed with four spines, three of which are on the gastric region, one 

 (obsolescent) on the cardiac region. Orbit incomplete, bounded externally 

 by a slender spine. Outside of, and just below the base of the second an- 

 tenna the antero-lateral angle of the carapace is drawn out into another 

 rather stouter spine. Just behind this, and from a little higher level, 

 a strong, sharp flattened horn is directed outward, forward, and a little 

 upward ; this horn is broad at the base, and furnished with a low carina 

 above, which is continuous with a rounded ridge, which runs inward to the 

 external orbital spine. A longitudinal carina on each side of the gastric 

 region, armed with a small spine a little way behind the middle ; from this 

 spine another ridge runs upward and inward, meeting the median carina at 

 the base of the third spine. The branchial regions are traversed by a series 

 of ridges which anastomose in such a way as to divide these regions into a 

 number of cells of various sizes, and they are armed with three small spines, 

 the anterior of which is the largest. The arrangement of these branchial 

 ridges and spines will be understood by a glance at the figures on Plate 

 XXXIV. The hepatic region is much inflated. 



The abdomen is ornamented with a low carina, most conspicuous on the 

 third segment, and on the sixth where it is double. There is also an in- 

 distinct and interrupted carina on each side, at the base of the pleurae. The 

 pleurae of the abdominal somites are acuminate, the posterior ones longer 

 pointed than those in front ; each abdominal somite except the first is fur- 

 nished with a transverse median ridge, interrupted in the middle ; on the first 

 segment this ridge is confined to the pleurce. There is a small spine at the 

 base of the hind margin of the pleurae of the fourth and fifth somites. The 

 sixth somite has two pairs of lateral spines (the posterior pair the larger), 

 and another pair at the hind end at the base of the telson. The telson is 

 long and acute, with a pair of longitudinal ribs on the dorsal side ; two pairs 



17 



