304 



mid-dorsal line and the posterior border, while the spiniform anterolateral angles are 6,7 mm 

 distant from one another ; the carapace is therefore but little more than one and a half as long 

 as wide and, the greatest height, above the 2"'^ pair of peraeopods, being as large as the greatest 

 width, it shows a rather stout shape. The rostrum, 3,5 mm. long, is a little more than one- 

 third as long as the rest of the carapace (Fig. 75 a) and reaches slightly beyond the far end of basal 

 antennular article; the distal half of the upper border is curved upward, the acute tip reaches, 

 however, not to the level of the gastric spine and, while the pro.ximal half of the upper border 

 is rounded, the distal lialf a])pears carinated. At either side of the base the rostrum is armed 

 with a slender acuminate spine, that extends as far forward as the eye; the two spines are 

 slightly directed outward and the distance, 0,84 mm., between their apices measures about one- 

 fourth the length of the rostrum. From each spine a sharp carina runs forward on the lateral 

 surface of the rostrum and curves towards the tip, which it does not reach and the curved, 

 carinated, lower border is fringed with feathered setae. 



In the dorsal median line the carapace is armed with two large, strongly compressed 

 and acute spines; measured in the middle line the distance between the ape.x of the anterior 

 or gastric spine from the orbital margin proves to be one-tenth the distance between the orbital 

 and the posterior margin of the carapace. The .slightly concave, carinated, upper margin of the 

 gastric spine extends to the posterior or cardiac spine, while the carinated upper margin of the 

 latter is curved and reaches to near the posterior border of the carapace; the anterior margin 

 of the cardiac spine is a little shorter than that of the gastric and both spines are larger than 

 the rostral spines. The distance, 3,9 mm., between the apices of the two spines is almost one- 

 third the length of the carapace, rostrum included. Orbital spine directed obliquely upward, small, 

 reaching not so far forward as the eye or the rostral spine. Post-antennal spine acute, directed 

 also obliquely upward and reaching a little beyond the level of the eyes, about to the distal 

 third of the rostrum. The infero-lateral border of the carapace is strongly curved: an elevated 

 ridge or carina runs from the obtuse antero-lateral angle, just below the post-antennal spine, 

 close to and parallel with it, to just behind the middle and from here unites with the infero-lateral 

 border itself. The lateral sides of the carapace bear each two carinae, of which the upper is 

 unarmed, the lower bispinose. The rounded upper carina runs on the level of the orbita' 

 spine, almost twice as far distant from the infero-lateral than from the upper border of the 

 carapace, the dorsal spines included; this keel begins near the posterior border and reaches, 

 -slightly curved and with the concave side turned towards the upper border, hardly beyond the 

 middle of the carapace. The lower keel is formed by two acute spines, placed i m mediate! )• 

 behind one another, almost in the same plane; the anterior spine, nearly 3-times as long 

 as the posterior, reaches to just beyond the tip of the gastric spine and the distance, 1,62 mm , 

 between the two lateral spines measures about one-fifth the length of the carapace, without tiie 

 rostrum and measured in the middle line. From the posterior spine the litde prominent and 

 rounded keel runs backward, but fades away at the posterior third of the carapace ; in front 

 of the anterior spine the keel also .soon disappears. This keel is separated from the gastric 

 region by the distinct, though shallow, hepatic groove, which is traceable to near the orbital 

 margin ; a shallow groove is also visible between the anterior lateral and the post-antennal spine. 



