124 Cumacea: 11. Diastylidae, 7. Leptostylis 



ascends surrounding a slightly impressed space with arched centre. Pedigerous 

 segments 1, 2 short, conspicuously narrower than the carapace or the next 

 2 segments, b^^ with postero-lateral corners little extended, blunt. Telson 

 as long as 6**^ pleon segment, with 1 pair of lateral spines in juv., 2 pairs 

 in adult. Antenna 1 short, 2"*^ joint of peduncle shorter than .3*^. Peraep- 

 pod 1 long and strong, last 3 joints of uniform length. Peraeopods 3, 4 

 in Q juv. with exopods 1-jointed. narrowly conical. Peraeopod 5 well deve- 

 loped in adult, the specific name alluding to the absence of these limbs 

 being no doubt due to observation of a young specimen. Peduncle of uro- 

 pods considerably longer than the telson. with 3 spines on medial margin 

 of young, 9 on that of adult, rami equal, rather shorter than the telson, 

 endopod with a single spine on each joint at end of the medial margin 

 which in the adult has a continuous brush of fine hairs. L. Q adult 

 10*5 mm. 9 juv. (uropods included) 7'5 mm. 



S. Atlantic, off mouth of R. La Plata, depth 98 m. 



2. L. antipus Zimmer 1907 L. a., Zimmer in: Zool. Auz., v.31 p. 223 | 1909 

 L. a., Zimmer in: Ergeb. Schwed. Siidp.-Exp., v.Q nr. 3 p. 22 t. 7 f. 119—127. 



Hirsute. Pseudorostral lobes shortly and bluntly produced; commen- 

 cing on these and running backwards a pair of carinae enclose a cordiform 

 space on the front of the carapace, of which the hind margin has a sharp 

 carina, contiimed some way forwards on the sides. Eyelobe minute. Pedi- 

 gerous segments 1. 2, produced forwards in a submedian pair of tooth-like 

 processes. Telson rather shorter than 6**' pleon segment, with 2 pairs of 

 lateral setae on the abruptly narrowed section and a pair of spines on the 

 anal valves. Antenna 1, 2'^*^ joint shortest, 3*^ longest, both flagella 3-jointed. 

 Maxilliped 3, 2"*^ joint nearly twice as long as rest of limb. 3*^ slightly wider 

 than ■i**^. Peraeopod 1 very long. i\^^ joint longer than o*^, 5**^ than 1^^. 

 Peraeopod 2, 7*^ joint nearly as long as 5*^. Peraeopods 3. -i, with exopods 

 rudimentary. Peduncle of uropods more than thrice as long as the telson, 

 and twice as long as the exopod, with 9 spines on the medial margin, 

 endopod 2/3*^^ as long as the peduncle, 1 ^^ joint much longer than 2""^, 2""^ 

 a little longer than ^i^, each with 2 spines on the medial margin. Colour 

 faintly yellowish white. L. 9 4 — 6 mm. Adult d unknown. 



S. (Teorgia, r5 juv. at 75 m; ^ at 12 — 15 ra and 252 — 310 m. 



3. L. ampixUaoeus (Lilj.) 1855 Cnma ampullacea, \V. Liljeborg in: UFv. Ak. 

 Forh., i;. 12 p. 120 | \mb Diastylis a., G. 0. Sars in: Forh. Selsk. Christian., 18(54 p. 175 | 

 1866 D. a., G. 0. Sars in: Nyt Mag. Naturv., v. 15 p. 105 | 1869 Leptostylis a., G. 0. 

 Sars in: Nyt Mag. Naturv., i'. 16 p. 344 | 1877 L. a., Meineit in: Naturh. Tidsskr., ser. 3 

 «;. 11 p. 178 I 1879 L. ampuUaceus, S. 1. Smith in: Tr. Connect. Ac. i'. 5i p. 114 | 1881 

 L. ampulacea, Meinert in: Naturh. Tidsskr., ser. 3 n 12 p. 497 | 1894 L. ampnllaceus, 

 A. M. Norman in: Ann. nat. Hist., ser. 6 v. 13 p. 277 ] 1896 L. ampullacea, G. 0. Sars in: 

 •Norske Nordhavs-Exp., v.Q nr. 15 p.24 | 1900 L. a., G. 0. Sars, Crust. Norway, v.3 p. 70 

 t. 50 f. 1 I 1900 L. a., Zimmer in: Fauna arctica, r. 1 p. -127.434 (with synonymy) | 1908 

 L. a., Zimmer in: Ergeb. Tiefsee-Exp.. ?;. 8 j). 182. 



Pseudorostral lobes shortly and not sharply produced, antero-lateral 

 corners rounded off and coarsely serrate. Carapace l3road, with scattered 

 hairs, eyelobe minute. Pedigerous segments 1, 2, produced forwards in a 

 submedian pair of tooth-like processes. Telson shorter than (i^^ pleon seg- 

 ment, with 1 pair of lateral spinules. Antenna 1. 3*^ joint rather shorter 

 tlian l^S much longer than 2"*^. principal flagellum 3-jointed, accessory 

 2-jointed. Peraeopod 1 not very long, 2"*^ joint not so long as rest of limb, 



