SYSTEMATIC DESCRIPTIONS CLYPEASTRINA. 



51 



Havana, Cuba. It is in the collection of the Comisi6n del Mapa Geol6- 

 gico de Espana, Madrid. 



Encope latus, new species. 

 (Plate 7, Figure 7; Text-figure 5.) 



The following is a description of this species: 



Test thin, very low, with very thin margin, wider than long. There 

 is an oval, rounded lunule in interambulacrum 5, almost exactly halfway 

 from the apical disk to the posterior border of the test. Deep notches or 

 emarginations in ambulacra I and V, also II, and by inference in IV as 

 well, though it can not be actually observed in this last-mentioned area. 

 The emargination in ambulacrum III is very shallow. The apical disk 

 is a trifle nearer the anterior border 

 of the test than the posterior, being 

 20 mm. from the anterior and 24 mm. 

 from the posterior border. From local 

 imperfections, details of the apical 

 disk can not be made out. The ventral 

 side is completely hidden in the matrix, 

 so that the character of the peristome 

 and periproct can not be given. The 

 ambulacral petals are relatively broad 

 and rounded. Petals I and V measure 

 13 mm. in length and are a little 

 longer than petals II and IV, which 

 measure 11 mm. in length and evi- 

 dently are longer than petal III, which, 

 however, can not be measured, as it 

 is imperfect distally. 



The single known specimen measures 43.5 mm. in length, 46 mm. in 

 width, and about 4 mm. in height. This species is very small and also 

 extremely thin and light for the genus, and it is not at all impossible 

 that the specimen described is an immature individual ; it is, however, 

 large enough so that it should have full species characters nearly or 

 quite developed. 



As the genital pores are not made out, it is possible that this species 

 should be referred to Mellita, which has 4 genital pores, rather than 

 Encope, which has 5. The specimen, however, has the look of an 

 Encope, so that it is referred to that genus. Encope latus approaches 

 E. annectans Jackson, of the Panama Canal Zone, but differs in the 

 proportionate size of the ambulacral petals, for I and V are the shorter 

 of all the areas in annectans. It also differs in the size, position, and 

 depth of the lunule of interambulacrum 5. 



Miocene (?) from the "Arecibo" (?) limestone, Government Road, 

 Aguadilla to Rincon, km. post 10, Porto Rico, 1 specimen, the holo- 

 type, station 122, American Mus. Nat. Hist. No. 18572, C. A. Reeds 

 collector, under the auspices of the New York Academy of Sciences, 

 the Porto Rican Government and the American Museum of Natural 

 History cooperating. 



FIG. 5. Encope latus, new species. Holo- 

 type, X 1. 



