Boone, Crustacea, Cruise of ''Alva,*' 1931 201 



Subfamily: Macrophthalminae. 



Genus: macrophthalmus Latreille. 



Macrophthalmus convexus Stimpson. 



Plates 104, 105 and 106. 



Type: Mr. Stimpson 's type came from the Loo Choo Islands, and 

 was originally deposited in the museum of the Smithsonian Institute 

 but is believed to be no longer extant. 



Dr. A. Milne Edwards's type of M. inermis was from New Cale- 

 donia and he also stated in his original description that this species is 

 also found in the Sandwich Islands. His specimens are deposited in 

 the Paris Museum. 



Distribution: Loo Choo Islands, (Stimpson) ; Penang, Singapore, 

 Indo-Malay Seas, (Miers) ; Koh Chang, Gulf of Siam, (Rathbun) ; 

 Amboina, (de Man) ; Mergui Archipelago, Gulf of Manaar, (Kemp) ; 

 Andamans, (Alcock) ; Kaiser Wilhelm's Land, New Guinea, Caroline 

 Islands, Fiji Islands, Tahiti, Society Islands, Samoa, (Kemp) ; Ha- 

 waiian Islands, (A. M. Edwards) ; Australia, (Haswell; Miers) ; Maur- 

 itius, (Miers) ; New Caledonia, (A. M. Edwards; Boone). 



Material examined : Eleven males and one ovigerous female taken 

 by the "Alva,'* at Noumea, New Caledonia, September 19, 1931. 



Technical description: Carapace high, rectangular, greatest 

 width from tip to tip of the anterolateral spines; median length in- 

 cluding the rostrum a trifle over one-half of this width, or exactly one- 

 half without the rostrum. The rostrum is a short median process, con- 

 stricted between the bases of the eyes and deflected, its frontal margin 

 wider and truncate, the outer angles widely rounded. The orbital 

 sinus extends the entire length of the carapace, with the inferior or- 

 bital margin projecting in advance of the superior margin, the wide 

 orbital concavity also dorsally exposed ; this inferior margin is moder- 

 ately oblique for the greater part of its length, then curving concavely 

 wider toward the anterolateral angle; the upper orbital margin is 

 slightly sinuate, the distal anterolateral angle acute, procurved ; both 

 orbital margins are beaded with regularly spaced, rounded tubercles 

 which diminish in size toward the center ; on the upper orbital margin 

 the carina is confluent with that of the rostral margin, which is devoid 

 of denticles. At the base of the anterolateral tooth on the outer mar- 

 gin separated by an acute sinus there is a smaller tooth. The lateral 

 margins are beaded, setose, moderately convergent, curved above the 

 bases of the fifth pair of legs, continuous with the posterior margin 



