100 ME, F, F. LAIDLAW ON POLYCLADS [May 26, 



the Polyclad fauna of the Indian Ocean, and especially of the 

 African coasts. 



As a matter of fact, I believe that no shore-haunting species have 

 hitherto been recorded from the East Coast of Africa, save from 

 the Red Sea and from the neighbourhood of the Cape of Good Hope. 



Of the four new genera described in the present communication, 

 Phylloplana is closely related to Leptoplana, whilst the other 

 three are of unusual interest. 



In order to keep the paper within reasonable limits I have 

 done little more than give an account sufficient, I hope, in each 

 case, to render the future identification of the species a matter 

 of certainty. I have not attempted to enter into any detailed 

 account of the anatomy of the various species, or to deal with 

 many of the interesting questions which have been suggested to 

 me by their structure. I have given a list of species of one or 

 two of the genera, with their distribution and some of their more 

 obvious characters, as I believe such lists may have some use. 



My thanks are due to Mr. Crossland, who has permitted me to 

 examine and describe this collection, and has furnished me with 

 useful notes and coloured sketches of some of the species. 



I am also indebted to Mr. A. D. Darbishire foi- drawings repro- 

 duced on Plate IX. 



Family Plaxocerid^. 



Planocera crosslandi, sp. nov. 



" White, leaf -like form. Dredged ofi" the mainland coast in 

 10 fathoms," Slightly damaged. 



Length 22 mm. 



Breadth 16 „ 



' ' Mouth " * from anterior end . . . 1 2 • 5 „ 

 S aperture from " movith," ... 4 ,, 



$ „ „ male 1-5 „ 



Tentacles from anterior end ... 6 ,, 



Only a single specimen collected. This species is most closely 

 allied to PI. armata mihi [5]. 



The eye- spots have an arrangement very similar to that found 

 in the latter species. There is a dense cluster at the base of each 

 tentacle ; the paired group of brain- eyes lying in front of the 

 brain is more extensive than that behind it. The epidermis 

 unfortunately has entirely disappeared from the surface of the 

 specimen. The muscles of the body- wall are very similar to those 

 found in PI. armata. The brain is well defined and of moderate 

 size. The gut has the character typical of the genus, viz. some 

 seven pairs of large branches from the main gut, each of which 

 gives ofi" numerous smaller ramifications which do not foi'm any 

 anastomoses. The gut is without the peculiar diverticula found 

 in PI. armata. 



* The tei-m " mouth" is used to mean the opening of the phaiyngeal pouch to 

 the exterior. 



