63 



f23. Penaeopsis Sibogae (de Man). 



Metapeiieus sibogae]. G. de Man, in: Notes from the Leydcn Museum, Vol. XXIX, 1907, p. 131. 



Stat. 306. February 8. 8°27'S., 122° 54.5 E. Lobetobi Strait. 247 m. Sandy mud. 11 malcs 



and 9 females. 

 Stat. 312. February 14. 8°i9'S., ii7°4i'E. Saleh-bay, North coast of Sumbavva. 274 m. Fine, 



sandy mud. i female. 



A new species closely related to Pen. conigcr (W.-Mas.), to the variety andamanensis 

 (\\^-Mas.) and to Pen. philippinensis (Sp. Bate). 



The numerous specimens are nearly all of the same size, the males attain a length of 

 70 mm., the females grow 80 mm. long. Body tomentose. The rostrum that has a more 

 si en der form than in the quoted species, is, in the male, a little longer than the rest 

 of the carapace and usually reaches just beyond the tip of the antennal scales for a very short 

 distance; rarely it reaches only as far as that tip. The rostrum, rarely quite straight, has usually 

 the distal half or third part more or less curved upward. In the female the rostrum is longer 

 and about o n e and a h a 1 f as long as the rest of the carapace ; usually it reaches with one- 

 third or one-fourth of its length beyond the tip of the antennal scales, rarely it extends only just 

 beyond it. In addition to a small, epigastric tooth, situated at the anterior fourth of the carapace 

 or just behind it, the rostrum is armed with S or 9 small teeth, that are all situated on the 

 rostrum itself; these teeth become smaller and further apart according as they approach the 

 extremity, but the very small, foremost tooth is often situated closer to the preceding tooth 

 than the latter to the antepenultimate. The lower margin is fringed with long hairs to beyond 

 the middle. No post-rostral ridge behind the gastric region. There is a distinct post-ocular 

 angulation, but hardly a tooth. Post-antennular (antennal) spine moderate, not continued backward 

 as a distinct ridge, post-antennular groove therefore quite shallow. Branchiostegal spine small, 

 as in Pen. coniger. Hepatic spine a little smaller and situated somewhat lower than the antennal 

 spine. Grooves of the carapace as feeble as in Pen. coniger var. andamanetisis. 



As regards the shape, the carination and other characters of the abdomen this species 

 fully agrees with the var. andamanensis ; as in this variety there are obscure traces of sub- 

 carinae on the 4* and ó^^^ terga. The 6"^ abdominal somite is twice as long as the 5*, a trifie 

 longer than the telson and a little shorter than the carapace, without the rostrum ; the telson, 

 as regards its form and toothing, also resembles Peii. coniger var. andamanensis. 



Eyes large. Antennular peduncle a little longer than the carapace without the rostrum, 

 and measured near the dorsal median line ; the very slender and acuminate stylocerite is regularly 

 curved upward and just as long as the eyes; the 2"'^ article, shorter than the i^', is twice as 

 long as the 3''<i. The inner (lower) flagellum is, in the male, one and a half as long as the 

 peduncle, i. e. the distance between the frontal margin of the carapace and the tip of the 

 peduncle; in the female this flagellum appears almost as long, i. e. very little longer than the 

 peduncle. The upper flagellum appears in the male one-fourth shorter than the other, and it is 

 but little longer than the peduncle, its widened proximal portion is slightly shorter than the 

 rest; the shorter flagellum of the female shows the same length as in the male, but the proximal 

 widened portion is much longer, 3-times as long as the filiform distal part. As in Pen. coniger 



6.^ 



