746 



SUMMARY OF CUKKKNT l;KSK \ I ; < I L Ks IM'.l.ATlXG TO 



Ichthyological Notes.* — II. Chas. Williamson communicates notes 

 on young stages of the angler {LopMus piscatorvus) ; on eggs of halibut, 

 conger, tusk; on post-larval Arnoglossus ; on a rare angler (Himan- 

 tolophus remhardtii) landed at Aberdeen ; on the occurrence of a 

 pilchard off Aberdeen ; on an angler with one eye; on three cases of 

 hermaphroditism in the cod ; on tumours from the cod, etc. ; on sand- 

 eels and a hermit-crab encysted in the abdominal cavity of haddock, 

 cod, and saithe ; and on the partial separation of the pectoral fin from 

 the snout in Raia circularis and R. clavata. 



Ambi-coloured Flatfish.f — Richard Elmhirst describes a number 

 of ambi-coloured flatfish from the Clyde — plaice, witch (Pleuronectes 

 cynoglossus), dab (P. limanda), flounder (P. ftesus) and turbot. 



INVERTEBRATA. 



Jffollusca. 



Layers of the Molluscan Shell.J — A. R. Horwood gives the fol- 

 lowing summary of the nature of the shell layer in Molluscs, omitting 

 cases which do not conform to the usual type — e.g. Patella, Fusus, 

 Littorina, Purpura, Ostrea, Peclen, Ghama, Spondylus, and Mytilus. 



Group. 



Gastropoda 



Lamellibranchiata 



Cephalopoda 



Living. 



C Only layer. Aragonite with 

 chitinous substance (con- 

 chiolin), rarely sulphate 

 of lime. 



1. Outermost layer dark, 



horny conchiolin. 



2. Outer prismatic calca- 



reous layer of calcite. 



3. Inner layer, lamellar 



porcellanous arago- 

 i nite. 



1. " Black layer." 



2. Porcellanous laminar 



aragonite. 



3. Nacreous calcite. 



Fossil. 



Only layer. Aragonite usu- 

 ally found as casts, but 

 sometimes as aragonite, 

 sometimes as granular 

 calcite. 



1. Absent. 



2. Calcite. 



3. Aragonite, usually pseudo- 



calcite. 



1. " Black layer," rare. 



2. Aragonite. 



3. Aragonite. 



Out of 101 species examined, 24 have a shell-layer of aragonite — 

 10 Gastropods (the inner and only layer), 10 Lamellibranchs (the inner 

 of two layers), 4 Cephalopods (the outer of two layers). 



a. Cephalopoda. 



New Cephalopods from Hawaiian Islands. § — S. Stillman Berry 

 describes Stephanoteuthis hawaiiensis g. et sp. n., with short saccular body, 

 large broad head, short stout arms, very large semicircular fins placed 

 somewhat posteriorly, and no gladius. He also describes Polypus hoylei 



* Fishery Board for Scotland, 28th Rep. (1911) pp. 24-67 (5 pis.). 



t Ann. Scot. Nat. Hist. (1911) pp. 77-9. 



j Geol. Mag. viii. (1911) pp. 406-18. 



§ Proc. U.S. Nat. Mus., xsxvii. (1910) pp. 407-19 (9 figs.). 



