004 



MR J. W. GREGORY ON THE MALTESE FOSSIL ECHINOIDEA. 



Distribution. — Malta — Globigerina Limestone (Coll. Brit. Mus.). 



Diagnosis* — Form elongated, cylindrical. The test is widest at a third of its length 

 from the posterior margin ; the anterior end is well rounded, and from this the lateral 

 margin curves gently to the widest point ; thence there is a straight sharp tapering to 

 the narrow flat posterior margin. Seen from the side the anterior margin is tumid, and 

 the posterior is vertical ; the greatest height is near the posterior end. The lower 

 margin is wavy. 



Apical system excentric anteriorly ; three genital pores. 



Ambulacra : Petals almost equal ; inuer pores smaller than the outer. Petals wide ; 

 closed below. The lengths of the poriferous zones on each side of the ambulacra are 

 almost equal. 



Mouth large ; placed before the centre, in a depression. Phyllodes large and wide ; 

 bourrelets very slightly raised. 



Anus high on the vertical posterior margin ; above a slight groove. 



Dimensions — ■ 







Brit. Mus., 



Dr Wright's 





No. 46,450. 



Figures. 



Length, 



18 mm. 



21 mm. 



Width, 





15 „ 



15 „ 



Height, maximum, . 





11 „ 



11 „ 



„ at post margin, 





8 „ 



8 „ 



Petals, length, 





5 „ 



6?„ 



„ width, 





2 „ 



2?„ 



„ No. of pores, 





12-13 





Apical system, distance froj 



m anterior margin, 



7 mm. 



9 „ 



Type. — Brit. Mus., 46,450. Dr Wright's type : locality unknown. 



Distribution. — Malta — Globigerina Limestone. Marsa Formo, Gozo — Third Nodule 

 Seam. 



Remarks. — The British Museum Collection includes two specimens of a species which, 

 though not quite of the same proportions as that figured by Dr Wright as Pygorhynchus 

 spratti, may be regarded as belonging to an elongated variety of that species. The 

 whereabouts of the type of the species is not known. 



The general form of the specimen, the vertical character of the posterior margin, and 

 the shape of the anus show that this species cannot be retained in the genus Pygo- 

 rhynchus, but must be removed from the alliance of Cassidulus to that of Catopygus. 

 From the type of this latter alliance this species differs in that the extrapetalous pores 

 are in a single series, and it therefore belongs to Prof. Duncan's subgenus Studeria. The 

 character seems to me, however, of fully generic value. 



Mr Cooke has collected two specimens, which agree closely with those in the British 

 Museum, from the third nodule of the Globigerina Limestone, and the other specimens 

 seem also to have been derived from this horizon. 



* Dr Wright having omitted to describe this species, only naming it on the explanation of the plates, a diagnosis is 

 here given. 



