28 discovery reports 



Revision of the Genus Psammobatis 



Genus Psammobatis, Gunther 1 



1870, Cat. Fish., vm, p. 470. Type P. rudis, Gunther. 



Malacorhina, Garman, 1877, Proc. Boston Soc. N.H., xix, p. 203. Type Raja tnira, Garman. 



This genus is closely related to Raja, but lacks the rostral prolongation of the cranium. 

 In the species in which mature males have been described, the anterior margins of the 

 disc are more or less distinctly notched, and the mixopterygia are long, slender, and 

 with their distal ends pointed and not expanded. Another feature is the frequent 

 presence in young and half-grown individuals of both sexes of a very small barbel-like 

 process at the tip of the snout, which may be borne on a small fleshy prominence: this 

 process sometimes persists in the adult. 



Key to the species 

 I. Interorbital width never very much greater than longitudinal diameter of eye; length of 

 eye + spiracle if to about 2 in that of snout, which is 4! to about 6 in width of disc. 



A. Interorbital width less than longitudinal diameter of eye; a triangular patch of enlarged 

 spines on the scapulary region ... ... ... ... ... ... ... extenta. 



B. Interorbital width equal to or rather greater than longitudinal diameter of eye; some- 

 times 1 to 4 median nuchal spines, but no scapulary spines ... ... ... scobina. 



II. Interorbital width 2 to 4 times longitudinal diameter of eye; length of eye + spiracle z\ to 

 nearly 4 in that of snout, which is 4! to about 7 in width of disc. 



A. Length of snout 4^ to 6| in width of disc, which is f to f of the total length of fish. 



1 . Length of snout 4^ to 4! in width of disc, 3 § to nearly 4 times that of eye + spiracle ; 

 vent nearer to tip of snout than to end of tail ... ... ... ... ... microps. 



2. Length of snout 55 to 63 in width of disc, z\ to 2 \ times that of eye + spiracle; vent 

 equidistant from tip of snout and end of tail or nearer to the latter ... ... lima. 



B. Length of snout about 7 in width of disc, which is about \ of the total length of 

 fish ... ... ... ... ... ... ... ... ... ... brevicaudatus. 



Raja zvaitii, McCulloch, from South Australia, has been associated with this genus 

 by some authors, but has recently been made the type of a new genus, Irolita, by 

 Whitley (1931, Rec. Austral. Mus., xvm, p. 97). 



Psammobatis extenta (Garman). 



Raja erinacea (non Mitchill), Ribeiro, 1907, Arch. Mus. Nac. Rio Janeiro, Xiv, p. 176, pis. xii, xiii. 

 Raia extenta, Garman, 1913, Mem. Mus. Comp. Zool., xxxvi, p. 356; Marini, 1928, Physis, 



ix, p. 278, figs. 

 Malacorhina cirrifer, Regan, 1914, Ann. Mag. Nat. Hist. (8) XIII, p. 16. 

 Psammobatis cirrifer, Regan, 1914, Brit. Antarct. {'Terra Nova') Exped. 1910, Zool. I (1), 



p. 2i, pi. xiii. 

 Raja cirrifera, Ribeiro, 1923, Faun. Brasil., Peixes, 11 (1), fasc. 1, p. 33. 

 Psammobatis bergi, Marini, 1932, Physis, XI, p. 140, 2 figs. 



St. WS 788. 13. xii. 31. 45°05'S, 65 00' W. Commercial otter trawl, 82-88 m.: 1 male 

 specimen, 260+ mm. (width of disc 180 mm.). 



1 Not to be confused with Psammobates, Fitzinger (1835), a genus of reptiles. 



