172 



V. Intermediate Shelf, Clay bottom, 27 to 65 Meters, Southern Gulf: 



Living only, clay bottom. 



Prosobranchiata 

 Architectonica nobilis 

 Crcpidula arenata 

 Crepidula excavata^ 

 Crucibulum lignarium 

 Crucihulum spinosum 

 Xenophora robusta 

 Natica broderipiana 

 Natica elenae 

 Polinkes uber 

 Distorsio constriclus 

 Distorsio decussatus 

 Bursa nana 

 Murex recurvirostris 

 Ocenebra, sp. 

 Cantharus capitaneus 

 Fusinus depetitthouarsi^ 

 Harpa crenata 

 Hormospira maculata 

 Conus arcuatus 

 Conus perplexus 

 Conus recurvus 

 Conus scalaris 



Scaphopoda 

 Dentaliuni oerstedii oerstedii^ 



Lamellibranchiata 

 Noetia delgada 

 Glycymeris tessellala 

 Chlamys circularise 

 Plicatula inezana 

 Plicatula penicillata 

 Anodontia edentuloides 

 Pseudochama saavedrai 

 Trachycardium belcheri 

 Pilar catharius 

 Megapitaria squalida 



Chione kelletti 

 Chione mariae^ 

 Semele paziana 



Crustacea 

 Balanus concavus mexicanus^ 

 Porcellana cancrisocialis^ 

 Clibinarius panamensis 

 Dardanus sinislripes^ 

 Paguristes praedalor^ 

 Pagurus gladius^ 

 Pagurus smithi^ 

 Pelrochirus californiensis 

 Pylopagurus varians^ 

 Hypoconcha lowei^ 

 Calappa sausserei^ 

 Cycloes bairdii 

 Hepalus kossmanni 

 lliacantha hancocki 

 Persephone lownsendi 

 Randallia bulligera 

 Porlunus acuminatus 

 Portunus affinus 

 Porlunus asper 

 Euphylax robuslus 

 Medaeus lobipes 

 Leilolambrus punclalissimus 

 Collodes gibbosus 

 Collodes tenuiroslris^ 

 Collodes lumidus 

 Paradasygius depressus^ 

 Pyromaia luberculala^ 

 Stenorhynchus debelis 

 Elhusa lata 

 Oediplax granulatus 



Holothuroidea 

 Thyonaeta mexicana 



VI. Outer Shelf, Clay bottom, 



Prosobranchiata 

 Archileclonica nobilis 

 Calyptraea conica 

 Crepidula excavata 

 Crepidula incun'a 

 Crucibulum serratum* 

 Crucibulum, n. sp.* 

 Distorsio constrictus 

 Distorsio decussatus 

 Ocenebra sloati, n. ssp. 

 Strombina clavulus 

 Strombina, n. sp.* 



66 to 120 Meters, Southern Gulf: 



Cantharus capitaneus 

 Cantharus, n. sp.* 

 Phos cococensis 

 Phos, n. sp. 

 Nassarius cattalus 

 Clathrodrillia, sp. 

 Hormospira maculosa 

 Pleuroliria oxytropis 

 Tiaturris spectabilis (dead ?) 

 Conus arcuatus* 

 Conus recurvus 



') Indicates same species found within the same depth range in the northern Gulf too. 

 * Most abundant and characteristic living species. 



