ON SOME OIGOPSID CUTTLE FISHES. 
75 
On Some Oigopsid Cuttle Fishes. 
By 
F. Ernest Weiss, F.E.S., 
From the Zoological Laboratory, University College, London. 
With Plates VIII, IX, and X, 
At the instance of Professor Lankester I have undertaken 
a careful examination of some of the Cephalopoda forming 
part of the valuable collection he has gradually acquired for 
the Museum of Comparative Anatomy at University College, 
London, 
All the species dealt with in this paper belong to the group 
of the Oigopsida, of whose anatomy and general structure our 
knowledge is at present still very scanty. This may be said to 
be especially the case with regard to some of the rarer forms, 
such as Chiroteuthis and Doratopsis, which I have been enabled 
to study. Besides these two my paper deals with some points 
in the anatomy of Iiistioteuthis Riippelli, Tracheloteu- 
this Behnii (Strp.), and Verauia sicula (Krohn). 
Chiroteuthis, Histioteuthis, and Loligopsis (including the 
form now called Doratopsis) were all united originally by 
D’Orbiguy 1 (1) in the family of the Loligopsidte, one of the 
most important and distinguishing characters of which was the 
absence of a valve in the siphon. 
Brock, in 1880, 2 divided the Oigopsidae into two groups, the 
Ommastrephes group and the Loligopsis group. To both he 
attributed the general Oigopsid characters, which included, 
1 D’Orbigny, ‘ Cephalopodes acetabuliferes,’ 1835. 
2 Brock, ‘ Morphologisches Jakrbuch,’ 1880. 
