45 THE ESSEX FIELD CLUB. 



Mr, Crouch called attention to the specimen of the Bittern, recently 

 found in the Zoological Gardens, at Regent's Park. 



Mr. Cole observed that the Bittern still occasionally occurred in Essex. 

 It was formerly found in the valley of the Roding. 



The Secretary exhibited on behalf of Mr. Whitehead, the Assistant in the 

 Museum, a specimen of Latliyyus m.icroyyhizus var. tenuifolius, from Epping 

 Forest, near Goldings Hill. There was some doubt as to the specific distinct- 

 ness of the form, and it was not at present known whether it was common in 

 Essex or not. 



Mr. F. W. Elliott exhibited bones found in the Forest at Monks Wood, 

 which had been gnawed by some rodent — he suggested by rabbits. 



Mr. Cole mentioned the curious fact that although there were so many 

 deer in the forest, antlers were but seldom found. Foresters affirmed that 

 they were eaten by some animals. 



An address was then delivered by Prof G. B. Howes, LL.D., F.R.S., 

 Professor of Zoology at the Royal College of Science, illustrated by slides 

 shown by the electric lantern. The following is an abstract of the address : — 



RECENT WORK ON MOLLUSCAN MORPHOLOGY. 



By PROF. G. B. HOWES, LLD., F.R.S. 



(A hstract) . 



Prof. Howes introduced his subject by briefly recapitulating the distinc- 

 tive characters of the Acephala, with especial reference to the fact that under 

 the burrowing habit and loss of the head respiratory organs had become the 

 accessories to alimentation. He then called attention to the recent work of 

 Drew, of Baltimore, U.S.A., on Yoldia limatula, particularly as concerning the 

 labial palps, siphonal filaments, and piston-like action of the branchiae, which 

 together with the formation of the anchor-like foot, were shown to collectively 

 furnish the acme of the physiological requirements of the acephalous 

 molluscan type. 



He then passed on to the consideration ot the Trochosphere and Veliger 

 larvae ; the former as exemplified by that of a marine worm ; the latter by 

 that of the o\ster with special reference to the absence of the "head"; and 

 by the late larva of Vcimctics, as bearing upon the origin of the cephalic eyes. 



Attention was then turned to the recent discovery, by Pelseneer, of eyes 

 in the adult Mytilidae, those oiMytUus being shown to be structurally of the 

 Patella type, but post-oral, and, though innervated by the cerebral ganglia, 

 distinct from the cephalic eyes of other molluscs. They were shown to agree 

 in position with the post-velar eyes of the Chiton larva, and thereby to suggest 

 a close connection between the Lamellibranchiata and Polyplacophora 

 (Chitons). The limits of modification and salient features in the anatomy of 

 the Chiton group were next indicated, leading up to the aplacophorous genus 

 Myzomenia [Dondersia] and special emphasis was laid upon Pruvot's recent 

 discovery that M. hanyulensis during development is the bearer of the 

 eight shelly plates of the true Chitons, and that the development itself 

 is passed through within a cellular "test," from which the young mollusc 

 escapes by a process of rupture. Referring to this "test" and its 



