584 PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [JuHG 20, 



17. Spikoebis clymenioides, spec. nov. 



Tube coiled, discoidal, compressed ; whorls usually three to four, 

 flattened or even fused together, with sinuo-radiate lines of growth ; 

 periphery carinate ; aperture constricted, circular ; nucleus with an 

 obsolete aperture nearly as large as the terminal one. 



The nearest species to this is S. sjoirulcea, Lam. (Spirulcea num- 

 mularis, Schlot.), from which the present species may be distinguished 

 in never having the last whorl produced or separated. 



San Pernando beds, Trinidad. Specimens frequently occur in 

 the cherty nodules, containing immense numbers of Orhitoides Man- 

 telli, Nummulina, Cardita, and the curious fossil next to be de- 

 scribed. 



CissEis, nov. gen. 



Body small, depressed, unattached, divided into rays ; oscula few, 

 large, generally disposed along the summits of the rays, and sur- 

 rounded by more numerous pores, which are developed on both 

 surfaces. 



18. CissEis ASTEKiscus, spcc. nov. 



Body divided into obtuse, somewhat carinate rays, generally four, 

 but occasionally more; oscula disposed along the summits of the 

 rays, and particularly on the subcorneal apex ; pores numerous. 



The oscula, or larger apertures, are disposed in a group of seven 

 or eight upon the apex, from which a row is continued along the 

 summit of each ray. The general form of the body is that of a 

 small Pcdmipes. Between the rays and towards the margins the 

 pores become smaller and less distinct. 



The nature of this body is so problematical that my object in 

 describing it is rather to make known its existence, and possibly to 

 obtain some hint as to its true nature, than to draw any inference 

 from its occurrence. It is found in considerable numbers among the 

 Orhitoides and Nummidince at San Eernando, in Trinidad. As it 

 appears by its structure to be more akin to the fossil sponges than to 

 any other organisms, I have described it as such, at the same time 

 giving it a generic name which does not involve any view as to its 

 true affinities. It may possibly be a Poraminifer ; but the nature of 

 the pores and the want of division seem to be against that view, 

 and the same characters appear to preclude our placing it with the 

 Echinodermata. In all the specimens I have examined the pores are 

 filled with a mineral infiltration, in a similar manner to those of the 

 Orhitoides. The structure is perhaps as near to that of Sjparsis^on- 

 (fia as to that of any other organism. 



III. Obsebvations on the Eelations oe the Caeibean Miocene 



P ATTN A. 



From the researches which have been made into West- Indian 

 Palaeontology it appears that the fauna of the Miocene period in 

 these islands presents some marked distinctions from that of the 

 United States, and had a stronger resemblance in several of its 

 leading characters to that of Europe, — not that there were no species 



