6 MAZATI.AN BETOZOA. 



Tlie wide, rounded or elliptical raised margiu of the mouths 

 of the distant cells gives the polyzoarium of the present species 

 a very pecidiar and well marked aspect. It is of a brownish 

 hue, or white. 



Hab. — Mazatlan ; on Imperator unguis ; L'pool Col. 



Tablet 15 contains a group on Imperator. — 16, a group de- 

 tached. 



Suborder II. CYCLOSTOMATA. 

 FAMILY DISCOPOEAD^. Bush, (ms.) 

 Genus DEFEANCIA, Brmn. 



13. Defeancia inteicata. Busk, (n. s.) 



Disco valde in^egidari ; irregulamter radiatim cosfulato ; ori- 

 ficiis tubidorum, porisque interstitiaUhus cequalibus magnitudine. 



The small in-egular patches appear to be constituted by the 

 confluence of sevci-al sets of costa3 with their corresponding 

 interstices, each set radiating from a depressed centi-al point. 

 It differs from D. deforrais Beuss, (L. e. p. 36. pi. 5, f. 24,) in 

 the uniform size of the openings of the tubes in the costse and 

 of the pores in the insterstices. 



Sab. — Mazatlan ; on Imperator unguis ; L'pool Col. 



Tablet 17 contains a group on Imperator. 



Besides the above, there occ\ir on some of the shells, indica- 

 tions of other species, but in too imperfect a condition to allow 

 of their determination. Among these perhaps the best marked 

 is a species strongly resemblmg Cellepora pumicosa, Lin., a 

 species of Lepralia, and of Tubulipora. 



CLASS TUNICATA. 



Omnia atlhuc ignota. 



