174 Cumacea: 24. Nannastacidae, 3. Nannastacus 



14. N. brevieaudatus Calm. 1905 N. b., Caiman in: Sci. Invest. Fish. Ireland, 

 1904 app. 1 p. 11,26 t. 1 f. 15-19. 



g. Near to N. miguiculatus (m. 15), but pseudorostral lobes very 

 short, not rising above eyes in lateral view, antero-lateral corner less pro- 

 duced, rounded at apex, finely serrate below. Surface of carapace rough 

 with prominent granules but with no flattened spines. Pedigerous segments 

 with a few small spines near lateral margins. Pleon shorter and stouter, 

 telsonic segment with no median spine on hind margin. Eyes colourless 

 or with colour easily disappearing. Antenna 1, process on 2"*^ joint shorter. 

 In peraeopod 3 the 2^^ joint equals in length the remaining joints combined, 

 and in the 4*^ and 5*^ pairs is nearly two-thirds of their length. Peduncle 

 of uropods little longer than its distal breadth, endopod once and a half as 

 long as the peduncle and exopod about two-fifths as long as the endopod. 

 L. 1*8 mm. 



d. Near to N. ungidculatus, but scattered setae on surface more 

 numerous, pleon much shorter, serrations on its dorsal surface less distinct; 

 eye pigment much less dark, reddish brown; hinder peraeopods with 2"'^ joint 

 relatively longer, that of 4*^ pair nearly equal to remaining joints combined; 

 peduncle of uropods about two-thirds as broad as long, a little over half as 

 long as the endopod, which is about thrice as long as the exopod. Body 

 as preserved colourless. L. 1-9.5 mm. 



Ballynakill Harbour. 



15. N. unguieulatus (Bate) 1859 Cuma nnguiculata, Bate in: Ann. nat. Hist., 

 ser.3 V.3 p. 273 tf. 9, i, m, u \ 1865 Nannastacus binoculoides, Bate in: Ann. nat. Hist., 

 ser. 3 v.lb p. 87 t. 1 f. 4((5) | 1869 Nannasticus b., A. M. Norman in: Rep. Brit. 

 Ass., V.S8 p. 259 | 1879 Nannastacus miguiculatus, G. 0. Sars in: Arch. Naturv. 

 Kristian., «. 4 p. 109 t. 55— 57 | 1889 Nannasticus u. (part.), D. Robertson in: P. nat. 

 Hist. Soc. Glasgow, ser. 2 v.3i Tr. p. 49 | 1893 Nannastacus u., T. Stebbing in: Int. 

 sci. Ser., i'. 74 p. 305 | 1901 N. wiguiculata, T. Scott in: Rep. Fish. Board Scotl., v. 19 

 p. 276 I 1902 N. U7iguiciilattis, T. Scott in: Rep. Fish. Board Scotl., r. 20 p. 480 | 1904 

 N. u., Caiman in: Herdman, Rep. Ceylon Pearl Fish., v.2 p. 176 | 1905 N. «., Caiman 

 in: Siboga-Exp., nr.36 p. 12, 13 [ 1905 A.M., Caiman in: Sci. Invest. Fish. Ireland, 1904 

 app. 1 p. 25 I 1906 N. u., A. M. Norman & T. Scott, Crust. Devon Cornwall, p. 33. 



2 . Body short and plump. Integument hard, rough with little tubercles 

 and scattered hairs. Pseudorostral lobes not very long, upturned nearly 

 perpendicularly, with serrate edges, meeting below the branchial orifice;, 

 antero-lateral margin deeply concave, the lower corner being sti'ongly and 

 sharply outdrawn, the margin below coarsely serrate for a long distance 

 backward. The large carapace obliquely truncate behind, its medio-dorsal 

 line convex till near the rear, where a short depression is followed by another 

 rise, which is spinose; the former convexity carries 2 longitudinal rows of 

 spines, which are small compared with the curved rows of flattened spines 

 which flank the branchial regions to the rear. One or two similar spines 

 are found on the margins of the outstanding side-plates of each pedigerous 

 segment. These segments have also dorsally 2 rows of smaller spines. Such 

 spines are continued on the pleon, each row having 3 on the 5*^ segment, 

 2 on the 4*^ 1 spine only on each of the other segments. The telsonic 

 segment has a single spine on its obtuse apex. Eyes wide apart, very dark, 

 each with 3 corneal lenses. Antenna 1, 2^'^ joint apically produced, flagellum 

 3-jointed, accessory 1-jointed, rudimentary. Antenna 2 1-jointed, with 3 setae. 

 Exopods of maxillipeds 3 and peraeopod 1, 2, slender. Peraeopods 3—5 



