86 



Parapaguriis pilosimamis, with a wide distribution; one a holothurian, 

 Molpadia musciiliis, also with an extremely wide distribution in all seas; 

 another is a bathypelagic shrimp, Acanthophyra curtirostris ; and the fifth 

 is the pelecypod, Solemya agassizi, which was rarely taken alive, and 

 being very light (mostly periostacum) may possibly float some distance. 

 Although these stations, shown on fig. 3, were taken in abyssal depths, 

 most of them were less than 100 nautical miles from land, as the shelf is 

 very narrow along the Pacific coast of Mexico and deep basins lie very close 

 to land. This proximity to land may well explain the richness of fauna, 

 since upwelling and associated high surface productivity seem to be typical 

 of most of the areas where trawling was carried out. This high surface 

 primary production provides a rich accumulation of organic matter on the 

 bottom, both in the borderland basins, and on the slopes which descend 

 directly to the abyssal sea floor (Parker, 1961). The majority of the 

 invertebrates appear to be detritus or deposit feeders, which should thrive 

 in the organic-rich bottoms. A complete list of the invertebrates identified 

 so far from the 15 stations is given below. Of the 20 stations (successful 

 and unsuccessful) taken at abyssal depths all but two (1/5 m- Petersen 

 grabs) were made with various large trawling devices (Table III), similar 

 to those used by the Galathea and Albatross. For this reason, few small 

 animals were collected. These devices were: one mid-water trawl (on 

 bottom), six deep diving dredges, three 3-meter Agassiz beam trawls, 

 and of the one 12-meter, six 10-meter and one 5-meter otter trawls. 

 The mesh size of the bags for all of the trawling devices, including deep 

 diving dredge, was the same, as all net liners were made by the same men 

 from the same bail of material, being about 1 cm. in diameter. Many of 

 the typical mollusks are illustrated on Plate IX, X or can be seen in 

 Dall(1908). 



Octocorals 

 Anthomastus fitter i 

 Thouarella, sp. 

 Sckroptilum cf. durissimum 



Hexacorals 

 Caryophyllia diomedaea 



Polychaetes 

 Maldane, sp. 



Brachiopods 

 Macandrevia americana diegensis 2 



Pogonophora 

 Galathealinum bruuni (?) 



Monoplacophorans 

 Neopilina galathaea 



Gastropods 

 Puncturella cf. expansa 

 Solariella ceratophora (dead) 

 Solariella equatorialis 2 

 chitonous trochids (?) 

 Fusinus rufocaudatus 

 Tractolira sparta 



