VILL. On Some Teratological Specimens. By 'T. A, CHAP- 
MAN, M.D., F.Z.S. 
[Read March 6th, 1907.] 
Prare XM: 
Mr. KENNETH J. Morton recently sent me a specimen 
of Capnia atra with a three-fold tarsus on one hind-leg, 
and Mr. A. Bacot placed in my hands a specimen of Cato- 
cala nupta with a duplicate tarsus on the fore-leg. It so 
happens that a more unusual aberration of structure has 
occurred in a specimen of Hastula hycrana amongst those 
I have recently been rearing. Though the latter has 
probably nothing in common “with the other two, still as 
all are aberrations of structure they may be noted to- 
gether. I have illustrated them all in Plate XII; though 
somewhat diagrammatic, the outlines are fairly accurate in 
all important points, being from camera sketches. 
The specimen of Hastula hycrana is a pupa that pos- 
sesses jaws of the larval pattern. I have never before met 
with such a specimen, nor read of such an one, but this is 
possibly due to my defective literary explorations. 
It is perhaps necessary to make it clear that these 
mandibles are pupal structures. We see, and more often 
hear of, pupee, and even imagines with larval heads. Of 
these this description is accurate, the head is a larval 
head, ¢. e. the head of the larva, not cast at the moult but 
remaining 7 siéw and having within it the pupal and 
imaginal heads proper. 
These mandibles are not a persistence of larval man- 
dibles, but the pupal mandibles, failing to recede to the 
simple pupal form, but taking on one almost identical 
with that characteristic of the larva. 
On the plate Fig. 1 represents the head parts from the 
front of a normal pupa. The maxille and labial palpi 
below, the labrum with two hairs basally and the small 
triangular mandibles (in this and many other species, 
quadrangular, the apex being truncate), in the angle 
between the labrum above and the maxillxe below, the 
apex just touching the labium. Figs. 2 and 3 represent 
the specimen we are considering. Fig. 2 nearly in profile, 
TRANS. ENT. SOC. LOND. 1907.—PART I. (JUNE) 
