OBSEEVED AT MOGADOE. 181 



Principally ia the river itself, but also in the spring at the Em- 

 peror's Garden with subvar. 1, abundant. Often carried down by 

 floods, and picked up pale and bleached on the sandy beach between 

 Mogador and the mouth of the river. Shell sometimes short and 

 ovate, but more frequently turreted acuminate, thinner in sub- 

 stance and lighter or paler coloured than subvar. 1, usually pale 

 horn or yellowish, with darker fulvous longitudinal wavy streaks 

 or lines, and more or less pellucid ; often bleaching to a pale-straw 

 colour, and acquiring a bright varnish-like polish, but scarcely 

 becoming thickened or opake. In sculpture it is no less variable 

 than in shape ; the ribs and nodules being sometimes strong and 

 regular, sometimes present on a part only of the volutions, and 

 sometimes barely indicated, and so gradually passing into j3 2, and 

 doubtless constituting, in such extreme state, f. 2078, 2079 of 

 Chemnitz's Buccina Maroccana, xi. 285, t. 210. ff. 2078-2083 ; 

 whilst certainly, considering their Moroccan origin, his ff. 2082, 

 2083 are more safely to be referred to the strongly -ribbed state of 

 this shell than to the oriental Melanopsis costata (Oliv.) (Lam. 

 ed. 2. viii. 489 ; Sowerb. Gen. f. 3, and Conch. Man. f. 315 ; Eossm. 

 ix. X. 41. t.50. fl". 678, 679), which may be really distinct, having 

 the suture deeply and strongly marked or impressed, and not as 

 in the present species, in both its varieties and all its Mogadorian 

 forms, flattened and obsolete. 



The shorter ovate forms of this subvariety are more strongly, 

 remotely, and regularly ribbed than the more turreted and elon- 

 gate ; the former having only 12-15, the latter about 20 ribs on 

 the last volution. 



^. laevigata ; costis nodulisque evanescentibus obsoletis. 



1. Subvar. mmor, testa parvula crassiuscula nigricante, apice plerumque 

 eroso-decoUata. 



Long. 3-6 v. 8 lin., apert. 2^4| ; Lit. 2-3i. 



Spring in the Emperor's Garden up the river at Mogador, inter- 

 mixed in about equal abundance with a 1, into which it passes by 

 imperceptible gradations. 



2. Subvar. major ; testa majore paUidiore nunc ovata nunc tunita, spira 

 ssepius acuta. 



a. Forma ovata, testa tenuiore. 



Long. 9-10 lin., apert. v. anfr. l-"' 6-0^ ; lat. 4J-4|- 



Melanopsis laevigata, Lam. ed. 2. viii. 490 ; M. buccinoidea, Fer. (recent), 

 et M.fusiformis (fossil), Sowerb. Gen. ff . 2, 5 ; Buceinum prcerosum, 

 Chemn. ix. ii. 40. t. 120. ff. 1035, 1036 (not Linn.), apice eroso-dceol- 

 lato; Melanopsis prarosa, Rossm. Ic. ix. x. 41. ff. 676, 677- 



