TATTEESALL— MYSIDACEA AND EUPHAUSIACEA 123 



I had named these specimens /S. paulsoni, Kossmann, and I am still inclined to think that 

 when male specimens of the latter species are discovered, S. (Bquiremis will be found to 

 be synonymous with *S'. paidsoni. None of the Sealark specimens are as large as the 

 single specimen, recorded as iS. paulsoni, from Ceylon by me (1906), but, otherwise, show 

 the closest agreement with the latter. After several years' preservation, no trace of the 

 distinctive colouration of S. aquiremis, mentioned by Hansen, can be discovered. 



Genus Hemisiriella, Hansen, 1910. 



8. Hemisiriella gardineri, n. sp. (Plate 6, figs. 1 — 5). 



Stations, w, Farquhar Islands, surface, two males, immature, 6 mm. ; oo, Amirante 

 Islands, surface, one male, immature, 6 mm. 



Form moderately slender. 



Carapace not very short, laterally leaving only part of the last thoracic segment 

 exposed, dorsally leaving the whole of the last and part of the penultimate segments 

 of the thorax exposed ; moderately produced anteriorly with the tip rounded. 



Eyes rather small, pigmented area occupying less than half the whole eye. 



Antennular peduncle (fig. 1) with the third joint about equal to the first and one 

 and a half times as long as broad. 



Antennal scale (fig. 1) about two and a half times as long as broad, reaching to 

 about the middle of the third joint of the antennular peduncle, terminal lobe broader than 

 long, about one-fifth of the entire length of the scale, terminal spine of the outer margin 

 strong. 



Antennal peduncle (fig. 1 ) as long as the scale, with the second joint almost three 

 times as long as the third. 



Third pair of thoracic limbs (fig. 3) without any transverse articulation on the sixth 

 joint ; dactylus distinct and slightly curved ; terminal brush of setye longer than the 

 dactylus. 



Fourth pair of thoracic limbs (fig. 4) extremely elongate, reaching when extended to 

 the end of the antennular peduncle ; sixth joint with a distinct articulation anterior to 

 the middle ; dactylus very rudimentary and hidden in the long terminal brush of setae. 



Pleopods in the male with the pseudobranchial rami on the second to fourth pairs 

 spirally twisted and the endopods and exopods of the third and fourth pairs similar, 

 without modified seta?. 



Telson (fig. 5) a little longer than the last segment of the pleon and about three 

 times as long as broad at its base ; constricted somewhat near the base after which the 

 margins converge gradually to a broadly rounded apex ; at the constriction the lateral 

 margins are armed by two rather long spines, then follows a short unarmed part of the 

 lateral margins after which the latter bear about eighteen spines which are arranged 

 distally in groups of five, four, three and five spines ; terminal spines at the apex, the 

 longest, about one-ninth of the total length of the telson ; between the terminal spines 

 there ai-e three subequal spinules and a pair of plumose setae. 



16—2 



