Cum.: 13. Oxyurostylidae, 1. Oxyurostylis, 14. Pseudodiastylidae. 1. Pseudodiastylis 133 



ment in 9, twice its length in 6, lateral spines in 6 or 7 pairs, nnspined apex 

 acutely upturned. Eye without pigment, visual elements indistinct. Antenna 1 9 

 with 2"fi joint of peduncle the shortest, principal flagellum 5-jointed in 9 with 

 3 -jointed accessory, in d the principal 5- or 6-jointed, with accessory 4- jointed. 

 Peraeopod 2 with the last 2 joints together not quite equal to the preceding 

 joint. Exopods on peraeopods 3 and 4 of 9 2-jointed but minute. Peduncle 

 of uropods scarcely longer than the telson. but longer than the rami, which 

 are subequal in 9 , in the 6 the endopod the longer, armed with many 

 more spines than in the 9 , its P* joint longer than either of the 2 following 

 joints. L. 9 6-6 mm., d' 7-3 mm. 



U. S. America, Casco Bay; Vineyard Sound, Woods Hole, surface; Punta Rassa, 

 Florida, depth 2 m; Calcasieu Pass, Louisiana. 



14. Fam. Pseudodiastylidae 



1912 Pseudodiastylidae, T. Stebbing in: Aun. S. Afr. Mus., v. lOv p. 133, 146. 



Telson long and narrow, with more than 2 apical spines. Antenna 1 

 large, with very small accessory flagellum. Antenna 2 of female with slender 

 terminal joint. Maxilliped 3 resembling peraeopod 1. Peraeopods 1 — 4 of 

 female with exopods, those of the 'i^ and 4*^ pairs rudimentary. Uropods 

 elongate. Male unknown. 



1 genus. 



1. Gen. Pseudodiastylis Caiman 



1905 Pseudodiastylis (Sp. un.: P. ferox), Caiman in: Siboga-Exp.. nr. 36 p. 1. 16 

 1908 P., Zimmer in: Ergeb. Tiefsee-Exp., v.8 p. 169, 170, 173 | 1912 P., T. Stebbing 

 in: Ann. S. Afr. Mus., u lOv p. 146. 



Pseudorostral lobes greatly produced. Carapace inflated. Telson narrowly 

 elongate, with three apical spines. Eye wanting. First antenna very large, 

 flagellum elongate, accessory three-jointed but minute. Second antenna of 

 female with terminal joint long, stiliform. Third maxilliped leg-like. Third 

 and fourth peraeopods of female with vestigial exopods. 



1 species. 



1. P. ferox Calm. 190.5 P. /., Caiman in: Siboga-Exp.. nr.36 p. 16 t. 2 f. 15— 2.t | 

 1908 P. f., Zimmer in: Ergeb. Tiefsee-Exp., ?\8 p. 17:) | 1912 P. /"., T. Stebbing in: Ann. 

 S. Afr. Mus., V. lOv p. 146. 



Integument armed with numerous spicules and spines, many of those 

 on the carapace being especially conspicuous and of complicated structure. 

 Pseudorostral lobes directed slightly upwards obliquely, curved, apically acute, 

 the production about one-third of the total length of the carapace; antero- 

 lateral corners spinose, slightly produced. Carapace oval, dorsal outline 

 strongly arched. The eyeless ocular lobe minute. First pedigerous segment 

 short but completely exposed; second and third segments seemingly immovably 

 united. Telson including the terminal spine nearly as long as the 3 preceding 

 segments combined; except at the base over the anal orifice its width little 

 over a twentieth of its length; 3 lateral pairs of spines are followed by 

 3 apical spines, of which the central is fully twice as long as the other 2. 

 Antenna 1 about three-fourths as long as the carapace, almost pediform, 

 pt joint equal to 2"^ and 3*^ combined, a little shorter than the flagellum, 

 of which the P* joint is long, the 5**^ minute; the 3-jointed accessory scarcely 

 one-sixth as long as the P*^ joint of the principal. Maxilliped 3 a little 



