182 PROCEEDINGf^ OF THE NATTONAL MUSEUM. vol.87. 



Distribution.— In the Patagonian and Peruvian zoological provinces 

 and the West Indian region. 



The animal is normally of a pinkish white dotted with dark red, 

 especially on the dorsal region. It has ten arms and an internal "pen" 

 or endostyle, which is plume-shaped with symmetrical vanes, as 

 represented in figure 2. This endostyle is of a cartilaginous material 

 and not shelly, as in some other genera, such as Sepia, etc. The 

 details of form are well represented by the figure. 



Beside the mollusks enumerated in the above report, Mr. Coker 

 collected the following species belonging to the Brachio])oda. 



DISCINISCA LAMELLOSA Broderip. 



Orhicula lamellosa Broderip, Proc. Zool. Soc. of London for lS:i3, p. 124; Trans. 

 Zool. Soc. London, voL 1, 1884, p. 142, pi. 23, fig. 2. 

 On Mytilus (Choro) at Ancon Bay. Of no economic importance. 



Distribution. — From the Island of Chiloe northward to the Gulf 

 of Panama, adhering like limpets to mussels, the timbers of old 

 wrecks, and even to the bottoms of vessels which remain at anchor 

 for some months. They occur from low-water mark to a depth of 

 9 or 10 fathoms. 



The shell is horny, rounded, and nearly flat, with a more or less 

 profusely lamellose surface; the upper valve is slightly convex, the 

 apex a little eccentric, the lower valve is flat, radially striate, very 

 thin, and pierced by a narrow foramen through which a fleshy 

 pedicel extends by which the animal adheres to solid objects. The 

 color is yellowish brown, and the diameter of these shells when nor- 

 mally develo])ed rarely much exceeds 25 mm. 



LIST OF THE PRINCIPAL WORKS RELATING TO THE MOLLUSOAN 

 FAUNA OF THE PERUVIAN ZOOLOGICAL PROVINCE. 



The following works are those most necessary for a study of this 

 fauna, though many others have been consulted for incidental 

 references. The abbreviations used in the faunal list to designate 

 some of the more frequently cited works follows the title in paren- 

 theses. 



Bayern, Therese, Princessin von. Im Jahre 1898, auf einer Reise in Siid-amerika 

 gesammelte Mollusken. Nachr. Deutsche Malak. Ges., J900, pp. 49-58, pi. 1. 



Bergh, Rudolph. Die Opisthobranchier der Sammlung Plate. Zool. Jahrb. suppl. 

 This is supplemental Bd. 4, pt. 1, 1898, pp. 481-582, 8°, pi. 6. (Fauna Chilensis). 



Bertin, Victor. Revision des Tellinides du Museum d'histoire naturelle. Nou- 

 velles Archives du Museum, ser. 2, vol. 1, 1878, i)p. 203-361, pis. 8-9. 



Revision des Donacidees du Museum d'histoire naturelle. Nouvelles Archives 



du Museum, ser. 2, vol. 4, 1879, pp. 57-121, pis. 3, 4. 



Revision des Garidees du Museum d'histoire naturelle. Nouvelles Archives 



du Museum, ser. 2, vol. 3, 1880, pp. 57-129, pis. 4, 5. 

 Boas, J. E. V. Spolia Atlantica, 1886, 248 pp. 4°, 8 pis. (see pp. 160-161). 

 Broderip, W. J. Descriptions of some new species of Calyptrseidae. Trans. Zool. 



Soc. London, vol. 1, 1834, pp. 195-206, pis. 27-29. 



