MACRUROUS DECAPODA OF THE SUDANESE RED SEA. 361 



more acute than they are on the specimen of corresponding size in the 

 present collection. 



Previously recorded from the Red Sea by Nobili (1906). 



GoNODACTYLUS demani, Henderson, 1893, var. SPINOSUS, Bigelou; 1893. 

 See Kemp, 1913, p. 165. pi. 9. fig. 112. 



Localities. Station V. D, 1 J" , 15 mm. Station XI., 2 ? , 22 and 32 mm. 



Bemarhs. The two specimens from Agig have the entire surface covered 

 with small spinules, densely packed. The small specimen from Khor 

 Dongonab has the telson very much of the form shown in Lenz (1905? 

 fig. 12), except that there is only one row of spinules on the submedian 

 teeth. In all three specimens the intermediate and lateral teeth of the telson 

 appear to me to be as well developed as in the typical form of the species. 

 All three agree in having the inner uropod armed with seta? all round. It 

 is this last character which has led me to refer these specimens to the 

 variety spinosus of G. demani. Bigelow (1894), when describing this form 

 originally, made no mention of the form of the inner uropod, but Lenz, in the 

 figure already quoted, shows the inner uropod invested with setae on the entire 

 margin. When Kemp wrote the main part of the text of his valuable mono- 

 graph, all the specimens, with one exception, of G. demani and its varieties to 

 which he had access had the inner uropod setose all round, and it was only 

 later (Addendum, p. 198) after he had examined a number of specimens from 

 the Gulf of Manaar, which all agreed in having the inner margin of the inner 

 uropod unarmed, that he became aware of this character. In Henderson's 

 figure of the type specimen the inner margin of the inner uropod is figured 

 as unarmed, and it seems to me to be just possible that the var. spinosus may 

 be constantly differentiated from the typical form by this character. If this 

 is so, then G. spinosus, Lenz has been correctly determined and is not a 

 synonym of G. demani, Henderson, as given by Kemp. As 1 have already 

 remarked, the tubercles on the telson of the typical form appear to be fewer, 

 larger, and more obtuse than in the variety, and it may subsequently be 

 discovered that this type of tuberculation goes with the unarmed character 

 of the inner uropod, to emphasise the distinction between the type and its 

 variety. Kemp does not give the character of the inner uropod of the 

 specimen from which his figure 109 was taken. This figure, as I have 

 pointed out, gives the general arrangement of the tubercles on the lelson of 

 those specimens which I have referred to the type form, all of which agree 

 in having unarmed inner margins to the inner uropods. In support of the 

 generally accepted opinion that G. demani and G. spinosus are varieties of 

 one species, I may observe that the copulatory organs on the first pleopod 

 of the male specimen from Khor Dongonab, referred here to the variety 



L1NN. JOURN. — ZOOLOGY, VOL. XX5IV. 28 



