^^^' 57'] FROM THE ISLAND OF ARRAN". 237 



beyond the groove. It seems probable, therefore, that the hinder 

 end of the shell was gaping. The truncation and groove remind 

 one strongly of the conditions found in Tancredia^ and at present 

 I know of no other genus that comes so near to this Arran shell.- 

 Unfortunately there is no evidence as to the hinge-teeth ; and 

 no known species of Tancredia has such distinct and regular 

 concentric ridges ; but in the absence of definite characters it is 

 proposed to place it provisionally in that genus, and in order to 

 associate it with the name of my colleague, it may be called 

 Tancredia (?) Peachi. 



DiTRUPA GLOBiCEPs (Queustedt). (PI. IX, fig. 21.) 



1858. Serpula glohiceps, ' Dev Jura ' p. Ill & pi. xiii, fig. 21. 

 1870. Serpula glohiceps, Tate, ' Irish Liassic Fossils ' Rep. Belfast Nat. Field Club, 

 App. i, p. 13. 



1876. Ditrypa glohiceps, Tate & Blake, ' Yorkshire Lias ' p. 438 & pi. xii, fig. 2. 



A portion of a Ser]pula-Y)k.Q organism, with two distinct enlarge- 

 ments or rings, agrees so well with the above species that there is 

 but little doubt as to its identity. This species has been found in 

 Ammonites angulatus-heds near Belfast, and in Yorkshire. 



DiTETJPA sp. 



One or two tapering and curved casts are almost certainly to be 

 referred to this genus. 



Serptjla sp. 



Indications of Serpula-tnbes are to be seen on several of the 

 specimens. 



Pentacrinus basaltipoemis (?) Miller. (PI. IX, figs. 22 & 23.) 



There are several specimens of basaltiform crinoid-stems : one 

 showing four ossicles united, and others only the impression of the 

 pentagonal and petaloid terminal face. 



Wood. 



There is one specimen of wood, but it is in so friable a condition 

 that nothing further can at present be said as to its structure. 



List of Liassic Fossils from Arran. 

 * Found in the North-east of Ireland. 



Cephalopoda. 

 ^Ammonites fJEgoceras) angulatus, Schlotheim. 



Gasteropoda. 



Amherleya acuminata (Cbapuis & Dewalque). 

 *Cerithmin Semele (?) Martin. 



Cerithium sp. (cf. C. Falaani, Dutnortier). 

 *Pleurotomaria tectaria, Tate. 



^ [The Key. J. F. Blake has called my attention to the resemblance which 

 this specimen bears to certain Aptychi ; and it may also be compared with Charles 

 Moore's figure of Fteromya Crowcomheia (Quart. Journ. Geol. Soc. vol. xvii 

 1661, pi. XV, fig. 23), but it can hardly be referred to either of those forms.] 



