Pleuromma abdominale Claus, 1863, p. 197, pis. V & VI. 



Pleuromma abdominale Brady, 1883, p. 46, pis. XI. XII 8e XXXI. 



Pleuromma abdominale Giesbrecht, 1893, pp. 347 & 356, pis. 5, 32 & 33. 



Pleuromma abdominale T. Scott, 1893, p. 41. 



Pleuromamma abdominalis Giesbrecht & Schmeil, 189S, p. 109. 



Pleuromma abdominale Cleve, 1901, p. 8. 



Pleuromma abdominale Wolfenden, 1902, p. 362. 



Pleuromamma abdominalis A. Scott, 1902, p. 405. 



P/euromamma abdominalis I. C. Thompson, 1903, p. 25. 



Pleuromamma abdominalis Thompson & Scott, 1903, p. 249. 



Pleuromamma abdominalis Cleve, 1903, p. 367. 



Pleuromamma abdominalis Wolfenden, 1904, pp. 11 1 & 112. 



Pleuromamma abdominalis Cleve, 1904, p. 195. 



Pleuromamma abdominalis Wolfenden, 1905 (a), p. 1010. 



Pleuromamma abdominalis Sars, 1905 (b), p. 2. 



Pleuromamma abdominalis Esterly, 1905, p. 174, fig. 33 a & b. 



Pleuromamma abdominalis Farran, 1908, p. 61. 



Pleuromamma abdominalis van Breemen, 1908, p. 104, fig. 1 19. 



This form appeared to be moderately common. It had a wide distribution in the Malay 

 Archipelago as shewn by the records now given. 



Stat. 37. — Stat. 40. — Stat. 66. — Stat. 71. — Stat. 106. — Stat. 1 10. — Stat. 1 17'. — 

 Stat. 118 (HENSEN vertical net, 900 metres to surface). — Stat. 128 (HENSEN vertical net, 

 700 metres to surface). — Stat. 141 (HENSEN vertical net, 1500 metres to surface). — 

 Stat. 142. — Stat. 143 (HENSEN vertical net, 1000 metres to surface). — Stat. 144. — 

 Stat. 146. — Stat. 148 (HENSEN vertical net, 1000 metres to surface). — Stat. 177". — 

 Stat. 185 (HENSEN vertical net, 1536 metres to surface). — Stat. i89 a . — Stat. 194 — 7. — 

 Stat. 203 (HENSEN vertical net, 1500 metres to surface). — Stat. 216. — Stat. 230 (HENSEN 

 vertical net, 2000 metres to surface). — Stat. 245. — Stat. 276 (HENSEN vertical net, 750 

 metres 'to surface). — Stat. 304. — Stat. 315. 



Plairoi?iamma abdominalis can readily be separated from the other species by the 

 structure of the fifth pair of feet of the two sexes. The luminous organ may be either on the 

 right or left side. The right antennule of the male is modified for grasping. 



The species is widely distributed in all the great oceans. It has been recorded by many 

 observers. 



Brady has apparently included figures of the next species, and also of Metridia Ineens 

 in his illustrations of Pleuromamma abdominalis. 



2. P lenromamma gracilis (Claus). 



Pleuromma gracile Claus, 1863, p. 197, pi. V. 



Pleuromma abdominale Brady, 1883, p. 46 (pars), pi. XI, fig. 11, pi. XII, fig. 13. 



Pleuromma gracile Giesbrecht, 1893, p. 347, pis. 5, 32 & 33. 



Pleuromma gracile T. Scott, 1893, p. 42. 



Pleuromamma gracilis Giesbrecht & Schmeil, 1898, p. 1 10. 



Pleuromma gracile Cleve, 1901, p. 8. 



Pleuromamma gracilis A. Scott, 1902, p. 405. 



Pleuromamma gracilis I. C. Thompson, 1903, p. 25. 



Pleuromamma gracilis Thompson & Scott, 1903, p. 249. 



Pleuromamma gracilis Cleve, 1903, p. 367. 



