280 



REPORT 1856. 



No. 



Name. 



No. of 

 Speci- 

 mens. 



Other Localities. 



488 



489 

 490 

 491 

 492 

 493 



494 



495 



49G 

 497 



498 

 499 



500 



501 



502 



503 



504 



505 



506 



507 



508 



509 



510 



51 



512 



513 

 514 



51 



516 



517 



Amphidesma pulchrum, Sow. 



striosum, n. s 



tortuosum, n. s 



ventricosum, n. s. (PKellia) 



Crassatella gibbosa, Sow 



Mulinia donaciformis, Hanl.[?'j . 



[? = M. anyulata, Gray.] 

 ventricosa, Gld 



[= Mactra exoleta, Gray.] 

 Lutraria elegans, Sow. (Mactra). 



Not L. undulata, Gld. teste 

 C. B. Ad. 



Mactra velata, Phil. 



Anatina alta 



(? Thracia or Periploma.) 



Pandora cornuta, n. s 



Potamomya sequalis, n. s 



inflata, n. s 



trigonalis, n. s 



Corbula bicarinata, Sow 



biradiata, Sow 



obesa, Hds 



ovulata, Sow 



rubra, n. s 



tenuis, Soiv 



, sp. a, like Taheitensis ... 



, sp. b 



Solecurtus affinis, n. s 



Solen rudis, n. s 



Pholas crucigera, Sow 



= crucifera, Sow. = cruciger, 

 Mull. 



tubifera, Sow 



xylopbaga, Val. (non Desk.) 



soft mud, under man- 

 groves, near h. w. & 

 outlet of small stream, 

 with Area tuberculosa. 



>> »» >> 



u.s., deep in sd.,l.w.+ 



[l.w, 



coarse sd. among st., 



sp. a, like lanceolata 



, sp. b 



Orbicula Cumingii, Brod... 



filling the bottom of an 

 old "dug-out," h. w. 



1 



1 



I v. 

 I v. 

 14 



6 v. 



10 

 I v. 



1 

 Iv. 



3 

 2 



260 

 21 

 6 v. 



7 



1 



1 v. 

 Iv. 



2 v. 

 10 

 55 



2 v. 

 I v. 



Carac, Cum. teste Sow. in P. Z. S. I 



Elena and Pan., Cum. teste So 1 



[Conct 1 



St. Elena &Xipix.,sdy.m.,llfm., C 

 * [Payta, Font 



The Atlantic analogue is L. car, 

 culata, Sav." 



[7-17 fm., C. 

 Rl. Llej., Carac, St. Elen., sdy. n , 

 Chiriqui & Carac, s.&m.,3-7fm.,C . 

 8° 57'-21° 32', 22-33 fm., Hds. 

 Xipix., Mont., Carac, sdy m.,7-17 , 

 [C\ 

 Bay Montijo, sandy m., 12 fm., Cu 

 [Maz., v 



" Like S. Caribceus." 



Is. Puna, B. Carac, Nicoya, soft sa 

 stone, §-t. ; soft stone, l.w. ; h 

 clay, 13 fm., Cum. 



Carac, in decayed wood, 10 fm., Cu 

 [Payta, Fonta. 



underside of st., 1. w. 



50 iPavta, St. Elena, 1. w.— 6 fm., Cm 

 I Chili and Peru, Desh. 



If this list of species be estimated according to the standard of judgment 

 followed in the Mazatlan Catalogue, which is necessary for a fair comparison 

 between the two, the following numbers will not be needed: — 



Univalves: 5,33,52,70,72,164., 174, 199, 211, 212, 216, 218, 241, 330, 

 334, 337, 343, 348, 349, 362, = 20. 



Bivalves'. 422, 432, 482, 483, 484, = 5. 



The names given to 459 and 471 are also not required. 



Others may be discovered on a comparison of specimens or figures (which 

 it is to "be hoped the Trustees of Amherst College, who possess the types, 

 will cause shortly to be published), though they are not recognized from the 

 descriptions alone. The discovery of a large number of deep-water species 

 was due to the hermit crabs. Certain observed differences of station between 

 Messrs. Cuming and Adams are very interesting; in a few there may be 

 error ; from others we learn what great latitude is allowed to some of the 





