BY. T. HARVEY JOHNSTON AND OTTO S. HIRSCHFELD. 77 
horizontal region, since the lateral projections do not involve 
this portion but cover the dorsal and ventral postero- 
lateral edges as a thin sheet. We have used the term 
“* perivisceral ccelome ”’ widely so as to include the peri- 
gastric cavity. The periesophageal cavity does not call 
for comment. 
L. bancrofti is closely related to both L. murphiana 
and L. anatina (L. rostrum). Type specimens have been 
deposited in the collections of the Queensland Museum, 
Brisbane, and the Australian Museum, Sydney. 
GENERAL REMARKS. 
Our brief acquaintance with the Lingulidz has led us 
to regard the following features as being of value for specific 
determination. Shell characters :—Opacity or transparency 
of the adult shell ; degree and extent of calcification ; general 
form of valves ; convexity of valves ; ratio of length to 
breadth ; maximum length; character of the umbonal 
regions ; presence or absence of well marked median ridges 
on the valves internally ; prevailing colour. Anatomical 
characters :—shape of ccelome ; arrangement of musculature ; 
disposition of setz ; branching of pallial sinuses ; pigment- 
ation of pallium ; shape of nephrostome ; coiling of intestine. 
The peduncular length should also be noted. 
The Queensland species fall into four groups, (a) L 
tumidula, (b) L. hians, (c) L. murphiana and L. banerofti 
which resemble L. rostrum in general appearance, (d) L. 
exusta which reminds one of a small and very narrow L. 
rostrum. 
Key to Queensland. species of Lingula, based on shell 
characters :— 
1. Breadth of valves Lana more than half 
the length; shell thin, reddish brown........ L. tumidula 
2. breadth of shel] not more than half length, shell 
greenish or copper coloured............00. 3 
3. a. valves very thin, horny, readily distorted so 
that beaks become very prominent in dried 
