v^^rs :5\\' from the Island of Malta, 191 



inwards. The anus is situated high up, immediately beneath 

 the caudal prolongation ; the base is convex, and a partially 

 naked space on each side of the sternal portion of the inter- 

 ambulacrum, indicates the track of the basal portions of the 

 posterior ambulacras. The tubercles of the upper surface (2 b) 

 are smaller and more closely set together than those on the 

 sides and base, where they are larger, wider apart, and more 

 fully developed. They are perforated and uncrenulated, and 

 surrounded by a circle of small tubercles. H. Cotteauii resembles 

 Spatangus {Hemiaster) acuminatus, Goldf., but it is more globose, 

 and its posterior half is neither so elevated, nor yet so wedge- 

 shaped as that species ; the single ambulacrum is larger and 

 wider, and the antero -lateral pair are more developed in the 

 German than in the Maltese form ; they resemble each other 

 in the interambulacrum in both possessing a tail-like terminal 

 process, and in having the posterior border obliquely scooped 

 out ; they are both, likewise, Miocene Urchins, S. acuminatus 

 being found in that terrain near Cassel and Diisseldorf (Ger- 

 many), and at Bordeaux and Blaye (France). 



Affinities and differences. — The depth and length of the am- 

 bulacral areas, with the great declivity of the anterior side of the 

 test, and the post-discal carina, with its caudate-like process, 

 serve to distinguish this species from H. Scillce. 



Locality and stratigraphical position. — Collected from bed 

 No. 4, the calcareous sandstone at Malta. We dedicate this 

 species to our friend M. Cotteau, the learned author of ' Etudes 

 sur les ;^chinides Fossiles du departement de PYonne,^ who has 

 most generously aided us in our studies, by contributing the 

 types of many of his species to our cabinet for comparative in- 

 vestigations. 



Hemiaster Scillce, Wright, n. sp. PI. VII, fig. 1 a-f. 



Syn. Spatangus crassissimus, Desmoulins, J&tudes sur les Jfechinides, 



p. 394. no. 30. 

 Echinus, Scilla, CJorp. Mar. pi. 10. fig. 4. 



Test globular, higher behind than before; ambulacral areas 

 short ; single ambulacrum the longest, forming a deep sulcus 



V on the anterior border; antero-laterals wide, diverging at an 

 angle of 44° ; postero-laterals not half the length of the ante- 



: riors, forming an angle of 56° ; both pairs form sulci on the 



/ sides of the test : posterior border squarely truncated down- 

 wards and outwards : the anus high near the dorsum : base 

 convex : mouth at the anterior third, with a large projecting 

 under lip. 



Dimensions. — Antero-posterior diameter 1 /^ inch, transverse 

 diameter 1/^ inch, height 1/^ inch. 



