1891.] MR. E. A. SMITH ON SHELLS FROM ADEN, 393 



admit. With regard to the two others he ohserves : — " I quite agree 

 that they are undistinguisha!)le from the common varius of our 

 coasts. Even M. Fischer, who only finds three species common to 

 the Mediterranean and Red Sea, admits as much (Journ. de Conch. 

 1871, p. 225)." 



Having most carefully studied the two shells referred to (only 13 

 miUims. in length !), I have no hesitation in pronouncing them 

 young examples of P. senatorius. One of them distinctly exhibits 

 the red curved lines upon the ribs which are so characteristic of 

 tvpical specimens of this species, and which are chiefly visible upon 

 the pale blotches wliich variegate the surface. The second specimen 

 agrees with the others in all respects excepting colour. It is of an 

 orange tint, varied with ohscure pale markings. 



With regard to the latter portion of Air. Cooke's comment I may 

 point out that M. Fischer should not be accredited with the view 

 that " only three species are common to the Mediterranean and the 

 Red Sea." He is only reviewing a paper by MacAndrew and 

 states " il n'en a trouve que 3 identiques." 



9. Lima inflata, Chemn. 



Only a few valves have as yet been quoted from Suez. This 

 species also occurs at the Philippines, for specimens from this 

 locality exist in the British Museum. Another Mediterranean 

 species, L. squamosa, has been shown ' to have a world-wide range. 

 L. rotundata, Sowerhy, from South Africa may be regarded as a 

 variety of the present species. 



10. Spondylus GiEDEROPUS, Linn. 



Mr. Cooke considers this species synonymous with S. aculeatus, 

 Chemn. ! He remarks : — " It is perhaps from want of critical power 

 that I am quite unable to separate these specimens [correctly 

 identified by MacAndrew with S. aculeatus, Chemn.] from the 

 well-known Mediterranean gcederopus. Lam." '' This sentence is 

 hardly comprehensible, for if there is one species in the genus 

 Spondylus more easy of recognition than any other, it is S. gcederopus. 

 This is not the place to discuss the differences which separate 

 this species and 5'. aculeatus, but I would remark they are so 

 obvious that I cannot imagine any conchologist failing to perceive 

 them. 



S. aculeatus is quoted from the Red Sea by Chemnitz ; it is 

 common in the Gulf of Suez (Vaillant; and it is also known from 

 the Gulf of Akaba (Arconati) and Mauritius (MacAndrew). 



11. MODIOLARIA MARMORATA, Forbes. 



( = ccBwoJiVa, Vaill.) 

 The shells from Suez, specimens of which are before me, presented 



1 Lisehke, Japan. Meer. Conch, vol. i. p. 162 ; Smith, ' Challenger ' Lamelli- 

 branehiata, p. 287. 



2 Ann. Mag. Nat. Hist. 1886, vol. xvii. p. 136. 



