Cumacea: 11. Diastylidae, 6. Paradiastylis 121 



6. Gen. Paradiastylis Caiman 



1904 Paradiastylis, Caiman in: Herdmau, Rep. Ceylon Pearl fish., v.2 p. 17:j 

 1905 P., Caiman in: Siboga-Exp., nr. 36 p. 20 | 1908 P., Zimmer in: Ergeb. Tiefsee- 

 Exp., V.8 p. 181, 182 I 1911 P., Caiman in: Tr. zool. Soc. London, v. 18iv p. 366 | 1912 

 P., T. Stebbing in: Ann. S. Afr. Mus., v. lOv p. 146, 147. 



Telson rather short, with few hiteral spines or none. Third maxilliped 

 with exopod only in the male. Third and fourth peraeopods in the female 

 ([uite devoid of exopods. 



3 species. 



Synopsis of species: 



/ Endopod of uropods with 1st joint twice as long as 2ud 



j and 3d combined 1. P. brevicaudatus 



] Endopod of uropods with 1st joint not longer than 2iid 

 ^ and 3d combined — 2. 



i Peduncle of uropods twice as long as pleon segment 6 2. P. brachyurus 

 "" \ Peduncle of uropods thrice as long as pleon segment 6 3. P. longipes 



1. P. brevicaudatus (Zimmer) 1903 Leptostylis hrevicatidata, Zimmer in: Zool. 

 Jahrb., Syst. f. 18vi p. 685 tf. W— Y | 1904 Paradlastijlis (?) b., Caiman in: Herdman, 

 Rep. Ceylon Pearl Fish., v.2 p. 175 | 1908 P.b., Zimmer in: Ergeb. Tiefsee-Exp., v.8 p. 181. 



Pseudorostral lobes horizontal, acute, antero-lateral corners subacute, 

 forming a well marked sinus. Eyelobe small, eyeless, with a pair of denticles, 

 carapace much sculptured, 2 strong teeth in line on the frontal lobe, followed 

 by a deep median depression of the hinder half of the carapace flanked by 

 a' pair of keels from which on either side 4 lateral forward curving keels 

 take their origin; hind margin dorsally raised. Pedigerous segment 4 the 

 longest, with a dorsal pair of quadrate impressions, ^^^^ with a postero-dorsal 

 upturned conical process. Pleon segment 5 the longest, telson slightly shorter 

 than the 6*^^ segment, its narrowed distal portion much shorter than the 

 broad proximal, with 1 pair of lateral spines and a small apical pair with 

 pair of setules adjacent. Antenna 1 rather long' and slender. Peraeopod 

 1 long. Exopods of 3^ and 4**^ pairs slightly developed, the specimen being 

 probably 6 juv. Peduncle of uropods more than twice as long as the telson, 

 which is rather longer than the endopod; P* joint of endopod about twice 

 the 2"^ and 'i^ joints combined, 2"'^ nearly twice the 3'^, spines of medial 

 margin respectively 5, 2, 1; exopod a little shorter than endopod. Colour 

 brown. L. d juv. about 9 mm. 



Japan: Enosima, depth 6—8 m. 



2. P. brachyurus Calm. 1904 P. brachyura, Caiman in: Herdmau, Rep. 

 Ceylon Pearl Pish., v. 2 p. 159, 174 t. 5 f. 76—90 | 1905 P. b., Caiman in: Siboga-Exp., 

 nr. 36 p. 20 [ 1908 P. b., Zimmer in: Ergeb. Tiefsee-Exp., v.8 p. 181. 



Pseudorostral lobes horizontal, acute, with a pair of divergent spines 

 at apex, antero-lateral corners not produced, rounded, serrate. Eyelobe twice 

 as broad as long, with a pair of denticles, no distinct eye. A median keel 

 bears 2 procurved teeth on front part of carapace, on each side 4 curved 

 ridges run obliquely down and forwards, the front one serrate, the lower 

 edges crossed by a curved row of spines running down and back from 

 pseudorostral lobes towards the lower margin; hind margin dorsally raised. 

 Pedigerous segment 5 without dorsal process. Pleon segments with slight 

 serrate dorso-lateral crests, 5*^ not longer than 6^^ telson a little shorter 



