27 

 la. Metapeneus conigek var. andamanensis, Wood-Mason. Plate IV., fig. 13. 



Metapenseus philippinensis -var. andamanensis, Wood-Mason, Ann. Mag. Nat. Hist. (6) VIII. 1891, p. 271: 

 Alcock, Cat. Ind. Deep Sea Crnst , 1901, p. 17. 



Distingiiislied by the uptilted and nearly straight rostrum ; by the indis- 

 tinctness of the subcaringe of the 4th — 6th abdominal terga; and by the form of 

 the thelycum. In the thelycum the part corresponding with the vertical limb of 

 the T is a broad, longitudinally-grooved plate, so undermined that all its edges 

 except the anterior limit of attachment are free: its posterior (free) edge is 

 strongly recurved inwards and is bilobed. 



The female may attain a length of b^ inches. 



There are 53 specimens in the collection, registered as follows :— 



20S7-2105 ^ 

 ~ Types. E. of North Andaman I., 185 fathoms. 



7381-85 



9 



3403 



10 

 3531 



10 



Off Port Blair, Andamans, 112 — 244 fathoms. 

 Off C. Oomorin, 143 fathoms. 

 Andaman Sea, 100 fathoms. 



}> " Investigator." 



8. Metapeneus stridulans. Wood- Mason., Plate V., fig. 14, I4ta-d. 



Crotalocaris stridtdans, Wood-Mason, MS name. 



Metapeneus sirididuns, Alcock, Ann. Mag. Nat. Hist. (7) XVI. 1903, p 526. 



Peneus velutinus (partinj) Spence Bate, Challenger Miicrurn, 188S, p. 253, pi. xxxiii., fig. 1. 



Characterized by the presence, in both sexes, of a pair of stridulating or- 

 gans, situated one on each side of the carapace, near the middle of the posterior 

 end of the branchiostegite, in such a way that the anterior edge of the 1st abdo- 

 minal tergum can play over them. Bach organ consists of a longitudinal row of 

 vertically-disposed ridges, which vary in number, being usually 5, seldom less 

 than 5, and occasionally as many as 12, or, in the female, more than 12. 



The species is a typical Metapeneus, and belongs to the same group as 

 M. pliilip-pinensis and coniger. 



Integument remarkably thick, hard, and tomentose. 



Rostrum nearly straight, uptilted, sometimes reaching to the end of the 

 antennular peduncle but often shorter, armed dorsally with 5 — 8 teeth, the last of 

 which is small and isolated (epigastric). No post-rostral crest. An indistinct 

 post-ocular denticle. Post-antennular (antennal) spine very strong, produced 

 backwards as a strong convexity defining a broad post-antennular sulcus. 

 Hepatic spine small ; cervical groove present only in its neighbourhood. Bran- 

 chial region not defined except by a short crescentic crease below the hepatic 

 spine. Anterolateral (antero-inferior) angles of carapace spiniform. A pair of 



