305 



Inferior apices of branchiae turned backward. 



First somite of the abdomen smooth. On the tergum of the second a posterior triangular 

 area appears a little elevated with regard to the larger anterior remaining part; this triangular 

 area is bounded by the posterior margin and anteriorly by two finely crenulated lines, that run 

 from just behind the middle of the tergum with a curve backward and downward, pas.sing into 

 the posterior margin of the pleura. The distance between the posterior margin of the carapace 

 and that of the 2'"' tergum is just as long as the length, 7,5 mm., of the 3"' tergum, when 

 we measure in a lateral view the distance between the anterior and posterior extremities of the 

 upper border in a straight line. The t,'^ tergum, rounded anteriorly, is produced and elevated 

 posteriorly to a distinctly compressed carina or gibbosity, which in a lateral view 

 appears regularly curved; the upper border is rounded transversely, smooth, hardly punctate, 

 shining and distinctly set off from the slightly concave, finely and closely ])unctate, lateral 

 parts; on account of this gibbosity the posterior margin of the 3'''' somite projects a little 

 backward, though it is rounded. The upper border of this crest widens regularly from before 

 backward and a transverse line or depres.sion at the anterior fourth of the tergum seems to 

 separate this anterior part from the crest. The smooth and rounded 4''> .somite measures a 

 little more than half the length of the 3"'. Fifth somite a little shorter than 4''', smooth, 

 posterior margin concave; from each lateral e.x.tremity a shallow groove runs forward, that 

 separates the tergum from the pleuron, though it fades away on the middle. Sixth somite a 

 little longer than 4"', flattened above and terminating at either side of the posterior margin 

 in an acute spine. 



Different from the three other species of this genus the abdominal pleura are smooth, 

 unarmed and resemble much those of Craiigon crangon (Linne), the anterior and posterior 

 margins being rounded or obtuse. 



Telson (Fig. 75(5) 8,5 mm. long, one-fourth the length of the abdomen and a little more 

 than one and a half as long as the 6"' somite; anterior third of upper surface grooved, the 

 rest rounded; there are two pairs of minute lateral spinules, that are easily overlooked, and 

 the spinules of each pair are not implanted in the same transverse line; a third pair occur at 

 the posterior end of the lateral margins and besides these the acuminate tip (Fig. 75 i"), which 

 is almost one and a half as long as broad at base, bears at either side a longer spine, 

 close to the minute spinule and reaching as far backward as the apex. Inner Hropod a little 

 shorter than telson, outer uropod slightly shorter than the inner, truncated at the tip and 

 without diaeresis. 



Eyes well-developed, not contiguous, globular, greatest diameter nearly one-seventh the 

 length of the carapace, rostrum included; the corneal portion, that occupies by far the greatest 

 part of the ophthalmopod, is distinctly faceted by small facets and the pale upper part of the 

 eye is surrounded by blackish pigment, except at the inner side, while the outer and lower 

 part are also of a light pale colour. 



The antennular peduncle reaches until the middle third part of the antennal scale; 

 looked at from below the basal joint appears a little longer than the 2'"' and 3^'' combined 

 and it is armed, immediately behind the middle of its lower border, with a small, forwardly 



SIUOGA-EXI'EDITIE XXXIX <;'. 39 



