140 



Cumacea: 16. Holostylidae, 1. Holostylis, 17. Pseudocumatidae 



Synopsis of species : 



( Third maxilliped with 3d joint much wider than 5th .. . 1. H. helleri 

 \ Third maxilliped with 5tli joint much wider than 3d . . . 2. H. gayi 



1. H. helleri (Zimmer) 1907 Diastylis h., Zimmerin: Zool. Auz., v. 31 i>. 221 

 1909 D. h., Zimmer in: Ergeb. Schwed. Siidp.-Exp., v.d nr. 3 p. 2, 15 t. 6 f. 84— 96 

 1912 Holostylis h., T. Stebbing in: Ann. S, Afr. Mus., v. 10 v p. 146. 



Pseudorostral lobes much and sharply produced in front of the small 

 eyeless eyelobe; antero-lateral corners subquadrate with denticulate margin 

 , stronger above than below. Carapace strongly beset with 



powerful teeth, of which 2 are especially so on each side 

 of the frontal lobe and one below it; besides there is a 

 close covering of microscopic denticles and the lower margin 

 is denticulate. Pedigerous segments 1 and 2 short, with 

 side-plates beyond width of carapace. All the pedigerous 

 segments and first 3 of pleon have medio-dorsal pairs of 

 warts or teeth, the latter form on the last 3 pedigerous and 

 first 2 pleon segments. On first 5 segments of pleon a 

 median dentate carina encreasing on successive segments. 

 , , • ^ V Telsou begins laterally dentate, narrows before the middle, 

 ^i y'lN with about 9 pairs of lateral spines and a stronger apical 

 pair. Antenna 1 short aiid weak. Branchial leaflets about 

 20. Maxilliped 3, 2^<^ joint nearly thrice the length of rest 

 combined, 5*i> narrower than 3<^ or 4:^^. Peraeopod 1 Avith 

 strongly dentate 2"'^ joint, and a medial distal tooth on 

 3<i and" A^^^ joints. Peraeopod 2, S^h joint not so long as 

 6*1' and 7^^' combined, 6*^^ little shorter than 7^^ Peduncle 

 of uropods about as long as the telson with some It) spines 

 on the medial margin. Rami about half as long as the 

 peduncle (text), exopod with 1^* joint much shorter than 2"*^. 

 slightly longer than the 1-jointed endopod which has about 

 11 spines on its medial margin. Colour yellowish white. L. 9 about 13 mm. 



South Georgia, depth 20 — 75 m. 



2. H. gayi (Nic.) 1849 Cuma g , H. Nicolet in: Gay, Hist. Chile, v.o p.220, 

 Crust, t. 3 f. 1, la— d | 1912 Holostylis g., T. Stebbing in: Ann. S. Afr. Mus., v. lOv p.l46. 



Pseudorostral lobes somewhat upturned; carapace inflated at the sides, 

 covered with transverse carinae to the rear; telson less than two-thirds the 

 length of peduncle of uropods, with 6 or 7 pairs of lateral spines and a larger 

 apical pair. Maxilliped 3 with 2^^^ joint twice as long as rest combined, 

 carrying many setae on the dilated and produced apex, 5*^ joint wider than 

 3d Qj. 4th_ Peduncle of uropods with 12 spines on medial margin: exopod 

 with 2 equal joints, rather more than half as long as the peduncle: endopod 

 more robust, as long as the telson. 1-jointed, with 7—9 spines on the medial 

 margin. L. o 6*5 mm. 



San Carlos, Chiloe, among Fucus. 



17. Fam. Pseudocumatidae 



1878 & 1879 Pseudocumidae, G. 0. Sars in: Arch. Naturv. Kristian., r.S p. 466; 

 v.A p. 59 I 1887 P., G. 0. Sars in: Kep. Voy. Challenger, v. 19 pars 55 p. 7 | 1893 P., 

 T. Stebbing in: Int. sci. Ser., i-. 74 p. 307, 312 | 1900 P., G. 0. Sars, Crust. Norway, 

 r.3 p. 72 I 1900 P., T. Scott in: Ann. Scott, nat. Hist., v. 9 p. 222 [ 1903 P., Zimmerin: 



Fig. 92. 

 H. helleri (Zim- 

 mer), telson and 



uropod. 



