26 5 



a lateral view and almost contiguous to the eyes. In both females the rostrum is armed with 

 two pairs of teeth that are larger, i. e. more prominent, than in the specimens from Stat. 316; 

 the rostrum of the young specimen trom this Station resembles that of the specimens from 

 Stat. 316. In the four females from the Stations 88, 178 and 211, that are young or of medium 

 size, the rostrum shows the sa me broad form as in the second ova-bearing specimen from 

 Stat. 45, being less than three-times as long as broad (2,2 — 2,7) and it is armed with 

 two pairs of rat her large lateral teeth; as in that female the rostrum, shorter than the 

 eyes, is har dl y turned upward. The rostrum of the specimen from Stat. 300, the single 

 male collected and 35,5 mm. long, is 3,5-times as long- as wide, a little shorter than the eyes, 

 slightly turned upward and armed with two pairs of rather large teeth. The preceding obser- 

 vations show that there are usually two, rarely three pairs of rostral teeth, that the rostrum, 

 n e v e r 1 o n g e r , but usually shorter than the eyes, is more or less distinctly 

 turned upward and that the genera 1 shape of the rostrum varies considerably. 



Like in Pont. abyssi S. I. Smith and occidentalis Faxon the carapace is armed dorsally 

 in the middle line with one cardiac and two gastric spines, but the anterior gast r ie 

 s p i n e is always considerably smaller than the posterior. In the specimens 

 from the Stations 45 and 316, like also in the younger female from Stat. 88, the anterior spine 

 (Fig. 636') is hardly visible by means of an ordinary magnifying glass and may easily be over- 

 looked, so that the microscope must be put in use; in the four remaining specimens (Fig. 63 c) 

 the anterior spine is a little larger, measuring about one-third the length of the posterior 

 gastric spine. In the typical Pon f. occidentalis from Panama, however, the two gastric spines 

 are o f the sa me si z e. In the present specimens the posterior gastric and the cardiac spine, 

 that are equal, are a little smaller than the hepatic and the epibranchial spine; the latter are 

 also equal and placed, like in Pont. occidentalis, in an oblique plane, but the hepatic spine 

 stands just in front of the posterior gastric. Like in Pont. gracilis S. I. Smith (Confer Th. R. 

 R. Stebbixg, South African Crustacea, Part III, 1905, PI. XXV, car.), the carinated lower margin 

 of the carapace terminates anteriorly in a microscopical spinale, situated a little posterior to 

 the post-antennal spine; this microscopical spinale, which often does not occur, being probably 

 worn off, must apparently be considered as the branchiostegal or as the antero-lateral spine 

 of the carapace. 



Orbital and post-antennal spine well-developed, the latter slightly in advance of the 

 eyes and usually a ' little turned outwa.rd. Carapace about twice as long as broad. A distinct, 

 prominent though rounded carina runs from the posterior gastric to the cardiac spine and from 

 the latter to near the posterior margin, gradually fading away ; anteriorly the carina gradually 

 disappears near the anterior gastric spinale. On either side of the carapace a similar, rounded 

 carina runs parallel with the dorsal crest, beginning at some distance from the posterior margin 

 and terminating in the epibranchial spine; the hepatic spine, however, is not buttressed by a 

 carina. Like in Pont. aöyssi, finally, a microscopical spinule occurs each side just back of the 

 supraorbital fissure; hepatic groove deep, distinctly separatecl from the supraorbital fissure. 

 Similarly as in the genus Parapenaeus a fine fissure runs horizontally and straight backward 

 from the orbital margin, just above the orbital spine, to near the epibranchial spine, where it 



S1BOGA-EXPEDITIE XXXIX a'K 34 



