279 



5. Potitophilus angustirostris de Man. PI. XXII and XXIII, Fig. 67 — 67c;. 



rontoplulns angustirostris J. G. de Man, in: Zoolog. Medcdcclingen uitgegeven vanwegc 's Rijk.s 

 Museum van Natuurlijke Historic te Leiden. igiS.Deel IV, Afl. 3, p. 163. 



Stat. 7. March 11. 7°55'.5S., ii4°26'E. Reef of Batjulmati (Java), r ova-bearing female. 

 Stat. 50. April 16/18. Bay of Badjo, west coast of Flores. Up to 40 m. Bottom mud, sand 



and shells, according to locality, i male. 

 Stat. 142. August 5/7. Anchorage off Laivvui, coast of Obi major. Plankton, at night, i very 



young specimen. 

 Stat. 164. August 20. i°42'.5S., 130° 47. 5 E. Between Misool and New Guinea. 32 m. Bottom 



sand, small stones and shells. 2 females without eggs. 

 Stat. 273. Dec. 23 26. Anchorage off Pulu Jedan, East coast of Aru-islands. 13 m. Bottom 



sand and shells. 1 female without eggs. 



Until at present only two .species of Pontophilus were known, in which the outer border 

 of the antennal scale is armed with a tooth, namely Pont, scu/ptus (Bell) and Pont, incisus 

 Kemp; Pont, angustirostris now appears as a third, in which this rare character is observed, 

 but, besides by this feature, this new form also in other characters and in its whole outer 

 appearance proves to be closely related to these two species. 



The largest specimen, the female from the east coast of the Aru-islands, is 17,7 mm. 

 long, measured in the middle line from tip of rostrum to tip of telson, the carapace, rostrum 

 included, being 4,5 mm. long, the abdomen 13,2 mm. The rostrum (Fig. 67, 67a, 67(5), which 

 is longitudinally channelled, measures one- fourth the length of the rest of the carapace and 

 reaches to the distal fifth of the pronated eyestalks; it terminates distally in two slightly diver- 

 gent, pointed spines, so that the distal border appears in a dorsal view strongly concave, the 

 depth of the concavity being slightly more than half as long as the distance between the apices 

 of the two spines. The lateral margins of the rostrum, which is very narrow, the breadth 

 in the middle being only one-fifth the length, the terminal spines included, are anteriorly 

 parallel and from about the middle curve regularly into the orbital margin ; they are, like the 

 latter, fringed with long hairs, that, as in Pont, incisus, partly conceal the eyes. 



Orbital margin entire, not notched. Orbital .spine well-developed, reaching to the middle 

 of the cornea and to the distal fifth of the rostrum ; the distance between the orbital spine 

 and the rostrum, measured transversely, is just as long as the rostrum without the terminal 

 spines. Antennal spine much longer than the orbital, reaching to the anterior border of the 

 2"'' joint of antennal peduncle and as long as the eyes; this spine is buttressed by a sharp 

 carina, that does not reach to the level of the hepatic spine. 



Carapace depressed, as broad as long, the rostrum excluded; as in Pont, incisus, a 

 .shallow groove runs transversely across the base of the rostrum. Just behind this groove one 

 observes, at one-fifth the length of the carapace from the level of the orbital margin, a small 

 sharp spine in the middle line, directed horizontally forward, while a sharp carina runs in the 

 mid-dorsal line from the posterior margin of the carapace about to the middle of it; from the 

 gastric spine also usually a sharp carina runs backward for a short distance, the two carinae, 

 however, are not continuous, but .separated by a short smooth interspace. The lateral sides of 

 the carapace show five longitudinal carinae, three of which end anteriorly in a sharp spine; 



