r)3<) Mr. B. B. Woodward on (he Forward Progress! en 



Batrachuides cryptocentrus, Cuv. & Val. 



Deptli of body 4J to 5^ in the length, leiigtli of licad 

 3 to 3j, width of head between opereles 3^ to 3^. Diameter 

 of eye 5 to 6 in length of head, equal to or slightly less 

 than interorbital width. One siil)opercular and two oper- 

 cular spines. ^Maxillary extending beyond eye. Lower juw 

 a little projecting. Teeth on vomer and palatines large, 

 uniserial, obtusely conical; 4 on vomer, 10 to 13 on each 

 palatine; lower jaw with a single series of similar teeth, 

 and anteriorly a patch of sharper teeth ; prcmaxillaries 

 with two rows of villiforui teeth. Head and body entirely 

 naked; head covered with small filaments, that aljove 

 the eye well developed. Snout with a fringe of lila- 

 ments; another fringe on lower jaw, four of which are 

 distinctly larger than the remainder. From above and below 

 base of pectoral two rows of open pores, appearing as white 

 spots, which become indistinct in the adult, extend backward 

 nearly to end of soft dorsal and anal respectively. Uor.sal 

 11126-28; spines short, almost entirely hidden under the 

 skin. Anal 22. Pectoral 21 ; a pigmented patch in the 

 axil, but no foramen Caudal 13^ rounded. Brownisli, 

 paler below, with ti-aces of darker vertical bands, disappear- 

 ing in the adult; fins edged with darker. In young and 

 half-grown individuals the throat is marbled with pale 

 irregular spots. 



Three specimens, 70-220 mm. in total length. 



LXI. — Note on the Forward Proyre.ssiou in its Shetl of the 

 Animal of the Nuutiloidea and Animonoidea. Compiled 

 from Notes left by the late G. C. Crick, F.G.S., by B. B. 

 AVOODWAKD, F.L.S. 



The three facts which are necessary to remember when 

 attempting to form a conception of the mode of growth in 

 the Nautiloidea and Ammouoidea are : — 



(1) Growth in bulk of the animal taking i)lace at regular 



intervals, terminated respectively l)y the formation 

 of a new septum. 



(2) Rigidity of the shell, necessitating a forward movement 



of the too bulky animal. 



(3) Faculty of secreting gas, which must not be allowed to 



escape from the chambers of the shell. 



