of (he ^^ Genus" Peiieus. 517 



Podo- Artliro- Pleuro- 



Somite. branchiaj. branchicie. branchite. Total. 



VII ep. r . . = ep. + r 



Vm ep. + I 2 . . = ep. + 3 



IX 2 1 = 3 



X ep. 2 1 = ep.+o 



XI ep. 2 1 = ep. + 3 



XII ep. 2 1 = ep.+:'. 



XIII 1 1 = "^ 2 



XIV .. .. = 



Total 5 ep. + I 11 +r 5 = oep. + 17+/- 



In addition^ a small filamentous vestige of an anterior 

 arthrobrancli is present on the penultimate thoracic somite 

 in all the species I have examined, which include, besides 

 the Canadian species, M. Joyneri, M. tenellus, M. Macleayi, 

 M. philippinemis , M. Richtersi, and M. Batei. 



List of the Species of Metapeneus, Wood-Mason. 



I. No marginal sublerDiinal articnlatbuj spines on tJie telson. Last pair 

 of thoracic leys icithout exopodite ; their menis, in the adult male, loith 

 a notch and spiyie or tooth at its j^roximal end. 



1. Metapeneus monoceros, Fabricius, Milne-Edwards, Ilist. Nat. Orust. 



ii. p. 415. — E. Africa to Japan and Australia. 

 {Metapeneus incisipes, Spence Bate, ' Challenger ' Macrura, p. 257, 

 pi. xxiv. fig. 2, seems to be identical with M. monoceros.) 



2. Metapeneus affinis, Milne-Edwards, op. cit. p. 416. — Karachi to 



Japan. 

 {Metapeneus pl(inicor7iis, Fabricius, according to Milue-Edwards, 



closely resembles M. affinis, but may possibly, since it has the 



antennular iiagella compressed, not be a Peneus at all.) 

 {Metaj)eneus mutatus, Lanchester, P. Z. S. 1901, ii. p. 572, pi. xxxiv. 



fig. 6, seems to be identical with M. affinis.) 



3. Metaperieus Joyneri, Miers, Ann. & Mag. Mat. Hist. (5) v. I8&0, p. 458, 



pi. XV. figs. 8-10. — Japan. 



4. Meta2)e7ieus Dohsoni, Miers, P. Z. S. 1878, p. 302, pi, xvii. fig. 2.— 



India and Ceylon. 



5. Metapenenshrevicornis,'M.i\r\e-'RA.w?iYdiS, op. cit. p. 417. { = M, avi- 



rostris, Dana, U.S. Expl. Exp., Crust, pt. i. p. (503, pi. xl. fig. 3.) — 

 Mauritius to Borneo. 

 {3Ietapeneus sp., Lanchester, P. Z. S. 1901, ii. p. 571, pi. xxxiv. fig. 7, 

 does not seem to difier essentially from M. brevicornis, Edw.) 



6. Metapeneus lysianassa, de Man, Journ. Linn. Soc, Zool. xxii. 1888, 



p. 290, pi. xix. fig. 1. — Orissa to Singapore. 



The follotviny species appear tohelong to this group, haviny no movable 

 spines 07i the margin of the telson, though the condition of the last pair of 

 thoracic legs as regards e.iojjodite ^c. is not on record : — 



7. Metapeneus tenellus, Spence Bate, ' Challenger ' Macrura, p. 270. — 



Japan. 



8. Metapeneus crucifer, Ortmann, Zool. Jahrb., Syst. Abth. v. 1890, 



p. 451, pi. xxxvi. figs. 5 a, b. — Japan. 



