400 PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Dr. Yasey kindly examined the seed and thinks it may be a Helio- 

 charis, but is not certain. Unfortunately, the writer has not had the 

 oi^portunity, from lack of material, of examining such a form as Baris- 

 sia oUvacca, a lizard that Cope has placed as the leading genus under 

 Oerrho7ioti,dw ; as far as our examination has gone, however, of forms 

 representing other genera, it should leave no doubt as to the sound- 

 ness of the classification in placing our apodal Opheosaurus in the niche 

 it now occupies. 



EXPLANATION OF FIGURES. 



Fig. 1. — Left lateral view of skull of Opheosaurus ventralis, life size : pm., premaxillary 



1, nostril ; n. , nasal ; m., maxillary ; I. , lacrymal ; /. , frontal ; j)f. , postfrontal ; 



p., parietal; sg. , squamosal ; po., pro-otic; pi., pterotic; o.q., osquadratum; 



cl., columella; c, corauoid ; d., dontary ; _;., jugal; jj*/., jiterygoid. 

 Fig. 2. — Skull of Opheosaurus ventralis seen from beneath, taken from a smaller specimen 



than Fig. 1, and enlarged: i', vomer ; pi., palatine; o. t., os transvcrs^im ; sq., 



squamosal; o. q., os quadratum; n. a.,nasalai)erture; p^ni.,pterygomaxillary 



vacuity; p<7., pterygoid ; tp., interpterygoid vacuity. 

 Fig. 3. — Lower jaw of Opheosaurus ventralis, life size, same specimen as Fig. 1, seen from 



above: c, coronoid; «./., articular facet. 

 Fig. 4. — Hyoid and scaj)ular arch of Opheosaurus ventralis, life size, seen from in front : 



if, hyoid ; Tr., trachea; c, clavicle; s., scapula ; cr., coracoid ; si., sternum. 

 Fig. 5. — Same from Gerrhonotus scincicaudus, letters indicate the same thing : gl. c, 



glenoid cavity. 

 Fig. 6. — Anterior view of vertebra, with its ribs, from Opheosaurus ventralis, from middle 



of spinal column ; n. s., neural spine; n, rib. 

 Fig. 7. — Anterior view of caudal vertebra from same specimen. 



Fig. 8. — Anterior view of vertebra that bears the pelvic arch, 0. ventralis, slightly en- 

 larged: U.S., neural spine ; ct., centrum; /., ilium ; 2>.^-, pubo-ischium; F., 



rudimentary femur. 

 Fig. 9. — Sketch of lateral view of pelvis of Gerrhonotus scincicaudus, slightly enlarged: 



tr., transverse process of vertebra; A., acetabulum. 



OIV CERTAHN ¥iIITIPETS AND tHITOlV!^ FROM THE ©EEP ^VATERS 

 OEF TME EASTERIV COAST OF THE UIVITEl) STATES. 



By 'W. H. DAI.I.. 



I have received from Professor Verrill certain limpets or patelliform 

 shells and chitons collected under his supervision off the southeast 

 coast of New England in deep water by the United States Fish Com- 

 mission parties in 1881, with his kind permission to describe them. 

 Though without particular beauty and of small size, the hope that these 

 specimens would prove of interest has not been disappointed. 



Limpets are generally shore or shallow water mollusks ; the connection 

 of certain peculiarities of ifcructure in them with their geographical 

 distribution, and the progressive development indicated by the char- 

 acters of different genera, have already been the subject of comment by 

 me.* 



* Sci. Results of the Expl. of Alaska, I, art. II, pp. 41-43, 1876. 



