THE ANIMAL LIFE OF THE GROUP. 483 



tentacles and all. is less than Iwo inches in diameter and is a beantiful blue 

 color. When stranded the soft parts soon disappear, leaving a white disk about 

 the size of a dime, which is often appropriately called "sea money." Tliere is 

 also another form ^'^ that is fairly common at times. It somewhat resendjles 

 the Portuguese man-of-war in that it is surface-swimming and bears on its 

 upper surface an oblique sail. It differs fs-om the man-of-w^ar most notice- 

 ably in having short rather than long pendant tentacles. 



A curious transparent balloon-shaped little animal'" with two long re- 

 tractile tentacles, Avith odd tag-like appendages attached, has also been taken 

 in Hawaiian waters. It belongs to a fourth family,4« which also includes an 

 odd transparent, many-ribbed cylinder-shaped animal,-^^ four or five inches in 

 length, one end of which is rounded, the other truncated and occupied entirely 

 by the immense mouth. As these animals are jelly-like, they seldom, almost 

 never, reach the shore. For that reason they are rare curiosities w^hen once 

 they are secured. It is a matter of interest to know, however, that as many 

 as twenty species of jellyfish or medusie-like animals have been reported by 

 Dr. A. G. Mayer as occurring in the collections made by the Albatross. 



]\T0SS-AXIMALS. 



Mention has been made of the sea-mats or moss-animals."'" They are 

 usually found attached to stones, forming an incrustation which, upon examina- 

 tion, seems to be made up of very minute cells each perforated by a small pore. 

 Besides the encrusting forms there are branching forms that reseml)le hydroids. 

 but unfortunately our fauna has not yet been studied, so that the species are 

 not known. 



Allied to the Polyzoa, and by most authors placed in the same i)hylum."'* 

 are the very rare, but very interesting, lamp shells ^'- or arm-footed animals. 

 The shells of these animals are so like the common clam shells in general foi-m 

 that they Avere once classed as a division of the mollusks. but they ma.v be dis- 

 tinguished from them by the fact that their valves are niu'(|ual in size, and ihat 

 they are attached by a small stalk which passes out tlii-ough a liole in the apex 

 of the larger valve. While it is to be presumed that species occur offshore, the 

 only examples ^s that have come under the writer's immediate observation were 

 a few delicately-colored specimens a half inch in diameter, secured in a small 

 collection of shells brought up in dredging operations in Honolulu harbor, jmd 



*^ Vellela pacifica. ^' U/iriiiij>li(ii-<i fiixiforiiiiii. *■'' Ctenoi)lii<riv. *" Borne sp. '•*' Poh/zon. 



^1 MoUiiscoiden. ^- Tirarhiainids. ""^ I'crebrdtiild sinii/tiiiicfi. 



Description m- ri.Ari:. 



1. MdcrohracliiuDi (ircuuliiiKitnis ( iininarurc). - ."uul .'{. Cmnpnn = (Alphcus) locvis. 4. 

 Macrohrachium grandemanus (mature). 5. Acia-a affinis. 6. rhiijipoflia f)i<1ou.rii. 7. Mc- 

 topograpsus messor. 8. Pala'moii pacificus. 9. FscudosquiUu ciliata. 10, 11. 12. Leptodius 

 sanguineus. 13. Etisus Icevimanus. 14. Nerocda austra1asi(F. 15. Leptodius sanguineus. 

 16. Lophozozjimii.^ dodone. 17. Acitra .tpeeiosa. 18. Phj/tiiodiits nitidus. 19. Xanthi(i.'< ca- 

 nalirulatus. 20. Carpiladcs MonticitUisus. 21. Trapezia ei/modoee inferwedia. 22. Trapezia 

 digitalis. 23. Ehymodius ungidatus. 24. 25. Rimocarcinus simpler. 20. 27. Perinea tnniida. 

 28. Domecia hispida. 29. Hippa adactyla. 



