356 Mr. C. Spence Bate on some Crustacea dredged Note on Aptychus. Through the kindness of the Rev. A. Griesbach of Wollaston_, I have lately received an interesting specimen of Ammonite {A. Walcottii) obtained by him from the lias of Northampton-shire, containing the remains of the anomalous body Aptychus or Trigonellites, By a fortunate fracture, the Aptychus, of a corneo-calcareous nature, was found imbedded in the matrix filling the last chamber, about 6 inches from the aperture; the two lobes are semi-elliptical in form, about 1^ inch in length by 1 inch in breadth, and exhibit the concentrical striated sur-face or lines of growth. PL V. D. fig. 1. The comparative rarity in England of these bodies in direct connection with the Ammonite, of which they are presumed to be the opercula, has induced me to record the above fact. Mr. Strickland has described the occurrence of similar bodies in the Ammonites from the lias of DefFord (Geol. Proc. iv. p. 45 J), and Mr. Moore in those from Ilminster. Bronn enumerates about forty species of Aptychus from the Jurassic and Cretaceous strata, a small proportion to the nume-rous Ammonites found in these formations. XXXV. — On some Crustacea dredged hy Mr. Barlee in the Shet-lands. By C. Spence Bate, Esq. [With a Plate.] Through the kindness of Mr. Barlee (whose indefatigable in-dustry has been of such benefit to conchology), I received the following Crustacea dredged by him off the Haaf, Shetlands, during the fall of 1851. Hyas coarctatus. Inackus Dorsettensis. Portunus pusillus. Ebalia Pennantii. Lithodes Maia. Crangon spinosus. Hippolyte Sowerbei. Barleei (new species). Nymphon gigantea. The distant locality from which these come make them worthy of being recorded, at a period when research is endeavouring to illustrate the fauna of particular districts.